4.07.2010

Triple Chocolate Mousse Cake



Do you ever see something and just HAVE to have it, or more specifically, do you ever see a recipe and just HAVE to make it? This happens to me pretty frequently while perusing food magazines, scanning Web sites, flipping through cookbooks, watching The Food Network, and so on. Most recently it happened while I was standing in the checkout line at Whole Foods. There in front of me was the latest issue of Cook's Illustrated, and there on the cover was the most decadent-looking chocolate mousse cake. I talked myself down from buying the issue -- reminding myself that I had recently signed up for an online membership to CI and would surely find the recipe there. When I got home, I put away the groceries more quickly than I ever have, jumped on my computer, and started searching CI's site. Sure enough, the recipe was there.


I read through it, checking out what each of the mouthwatering components consists of -- the bottom layer is a flourless chocolate cake, the middle is chocolate mousse, and the top is white chocolate mousse. Adorn it all with some chocolate curls, and you've got yourself one show-stopping dessert! I brought it to Jeff's parents' house for Passover, and the empty pan I returned home with was a measure of the true success of this cake.


Oh, but let me go on a short tangent about the pan. This cake uses a springform pan, so the sides can be taken off, leaving the cake on the bottom part of the pan to serve it. Trying to flip a cake like this out of a regular pan would just make a huge mess. Unfortunately, I didn't own a springform pan, just some small individual ones, so I had to go shopping for one. Actually, I guess that's not too unfortunate!

Jeff and I were heading back from bringing our winter clothes to storage (our storage unit is way outside of the city -- to save money), and I convinced him to stop at the Williams-Sonoma in Hingham, so I could get the pan before we cut it too close to when I planned to make the cake.

I don't know why, but I hadn't expected Williams-Sonoma to have springform pans in three different sizes. I stood there, staring at the pans, trying to decide which one to get -- because I didn't think to check that when I initially looked at the recipe -- when a sales associate came over. I asked her what size is most commonly used in recipes and somehow started talking about the chocolate mousse cake. Suddenly, she stopped me and asked if I was referring to the cake on the cover of Cook's Illustrated, and I said yes, that's the one! I was so surprised she knew about it (but since then I've come to find out that several other people saw that cake, and it stuck in their heads too.) She couldn't remember what size it was either, so Jeff started trying to get on the Cook's Illustrated site on his phone. As we were struggling to get mobile technology to work quickly and efficiently (it never does, does it?), the sales associate returned and told me it needed a 9.5-inch pan. She had called her mom and asked her to look in the magazine! This is just one of the many reasons I love Williams-Sonoma.Where else can you find people who care that much about cooking and baking?

So now that I knew I needed a 9.5-inch pan, we looked back at the three sizes there, which were 8, 9, or 10 inches. Now, isn't that just too funny? So the sales associate and I talked it over for a few minutes, and I decided to go with the 9-inch pan. It worked out perfectly.

Below is the recipe, rewritten for how I made this cake. I eliminated nitpicky things like double boilers. I never use a double boiler when I can just microwave. It's so silly to go through all that trouble. You can find the complete, original recipe on Cook's Illustrated's Web site. What's that you say? You still don't have a subscription... after all these CI recipes I've told you about? What are you waiting for? There's even a great step-by-step video that shows you how to make this cake and how to cut it so you don't ruin the layers.




Triple Chocolate Mousse Cake (adapted from Cook's Illustrated, November 2009)
(Printable version)

Ingredients

Bottom Layer

6 tablespoons (3/4 stick) unsalted butter , cut into 6 pieces, plus extra for greasing pan
7 ounces bittersweet chocolate , chopped fine (Ghirardelli Bittersweet Chocolate Baking Bar)
3/4 teaspoon instant espresso powder
1 1/2 teaspoons vanilla extract
4 large eggs, separated
Pinch table salt
1/3 cup packed light brown sugar

Middle Layer

2 tablespoons Dutch-processed cocoa powder
5 tablespoons hot water
7 ounces bittersweet chocolate, chopped fine (Ghirardelli Bittersweet Chocolate Baking Bar)
1 1/2 cups cold heavy cream
1 tablespoon granulated sugar
1/8 teaspoon table salt

Top Layer

3/4 teaspoon powdered gelatin
1 tablespoon water
6 ounces white chocolate chips (Valrhona discs)
1 1/2 cups cold heavy cream
Block of Callebaut bittersweet chocolate (for making chocolate curls or shavings), optional

Preparation

Bottom Layer

Preheat oven to 325 degrees. Butter bottom and sides of 9-inch springform pan. Melt butter and chocolate in medium bowl in microwave. (I originally melted the chocolate in a Pyrex measuring cup and then transferred it to a bowl. It's easier to just put it in a medium bowl to begin with.)


Stir in espresso powder. Cool slightly. Whisk in vanilla and egg yolks; set aside.


In stand mixer fitted with whisk attachment, beat egg whites and salt at medium speed until frothy, about 30 seconds. Add half of brown sugar and beat until combined, about 15 seconds. Add remaining brown sugar and beat at high speed until soft peaks form when whisk is lifted, about 1 minute longer, scraping down sides halfway through.


Using a whisk, fold one-third of beaten egg whites into chocolate mixture to lighten. Using a rubber spatula, fold in remaining egg whites until no white streaks remain. Pour batter into prepared springform pan, and smooth the top with a small offset spatula.


Bake until cake has risen, is firm around edges, and center has just set but is still soft (center of cake will spring back after pressing gently with finger), 13 to 18 minutes. (Watch closely. Mine was done at just 13 minutes. And don't doubt yourself. If the edges are firm and the cake springs back, it's done.)


Transfer cake to wire rack to cool completely, about 1 hour. (Cake will collapse as it cools. It's actually crazy how much it sinks!) Do not remove cake from pan.


Middle Layer

Combine cocoa powder and hot water in small bowl; set aside. Melt chocolate in medium bowl in microwave. Cool slightly.


In clean bowl of stand mixer fitted with whisk attachment, whip cream, granulated sugar, and salt at medium speed until mixture begins to thicken, about 30 seconds. Increase speed to high and whip until soft peaks form when whisk is lifted.

Whisk cocoa powder mixture into melted chocolate until smooth. Using whisk, fold one-third of whipped cream into chocolate mixture to lighten.


Using a rubber spatula, fold in remaining whipped cream until no white streaks remain.


Spoon mousse into springform pan over cooled cake and gently tap pan on counter three times to remove any large air bubbles; gently smooth top with offset spatula. Carefully clean any drips from the inside edges of the pan. Refrigerate cake at least 15 minutes while preparing top layer.


Top Layer

In small bowl, sprinkle gelatin over water; let stand at least 5 minutes.


Place white chocolate in medium bowl.


Bring ½ cup cream to simmer in small saucepan over medium-high heat. Remove from heat; add gelatin mixture and stir until fully dissolved. Pour cream mixture over white chocolate and whisk until chocolate is melted and mixture is smooth. Cool to room temperature, stirring occasionally, 5 to 8 minutes (mixture will thicken slightly).


In clean bowl of stand mixer fitted with whisk attachment, whip remaining cup cream at medium speed until it begins to thicken, about 30 seconds. Increase speed to high and whip until soft peaks form when whisk is lifted. Using a whisk, fold one-third of whipped cream into white chocolate mixture to lighten.


Using a rubber spatula, fold remaining whipped cream into white chocolate mixture until no white streaks remain. Spoon white chocolate mousse into pan over middle layer. Smooth top with offset spatula. Return cake to refrigerator and chill until set, at least 2½ hours. (I left it in the fridge overnight.)


To Serve

Take cake out of fridge 45 minutes before serving. Using the back of a paring knife, scrape along the edge of a block of chocolate to form chocolate shavings or curls.


Sprinkle these on top of the cake.


Run an offset between cake and side of springform pan; remove side of pan.


Clean and smooth the edges of the cake by running an offset around the cake.


Using a knife dipped in hot water, cut the cake into slices, Clean and rewarm the knife after each cut. Serve with a dollop of homemade whipped cream.




The bottom layer was amazing. I've made a few flourless chocolate cakes before, and I've always loved how moist they are. But because this one gets completely covered with chocolate mousse after it cools, I think it stayed even more moist than a plain flourless chocolate cake would. There was no way the edges could dry out.

The middle layer was my absolute favorite. It's the most amazing dark chocolate mousse. I even saved a little for myself. I mean my pan was a 1/2-inch too small. I couldn't possibly fit all the mousse in there. (Truth be told, I could, but then I'd have no leftover mousse to snack on!)

The top layer I could do without, but everyone else loved it. Let me explain. I despise white chocolate. It's not even really chocolate! (It doesn't contain any cocoa solids, which would technically constitute chocolate, and it's just sickeningly sweet and plastic-like if you ask me.) But when I make recipes, I usually follow them to a T and improvise the next time. So I made the white chocolate mousse knowing I probably wouldn't like it. I even bought Valrhona white chocolate discs at $16.99 per pound because I thought if I went with expensive white chocolate, that would help. It didn't. (CI recommends Guittard Choc-Au-Lait White Chips, but of course Whole Foods had every other kind of Guittard chips but the ones I needed. I think they are usually there though.) Next time I make this, I'll definitely just do a layer of homemade whipped cream on top of the rich chocolate mousse and cake. That would be right up my alley. But I'm the only one who didn't really like it, and if you like white chocolate, I'm sure you'll love it.



What do you think of white chocolate?

What's the most decadent dessert you've ever made?

62 comments:

  1. WHOA... yes please!! It's not even 10 am here on the west coast and I'm already thinking about how I can get my hands on something chocolate mousse-y. That looks divine, Megan! And your tip about running the offset spatula around the edges is great, I'll definitely be using that. Oh and I adore white chocolate and I'm sad that it has somewhat of a stigma.

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  2. WOW!!! nothing better than chocolate and when it's a triple chocolate dessert is a must try in my book. AWESOME and DEVINE are the two best word for this GREAT!!! dessert.
    Geri

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  3. Megan, you've outdone yourself! Not only does this cake sound delicious, but it looks spectacular! While I'm not a fan of white chocolate either (blech!) I do think the white layer looks pretty atop that luscious chocolate mousse.

    This one is a keeper for sure! :)

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  4. You are not alone; I have had this cake stuck in my head since seeing it in my issue of CI! I was going to make it before Christmas, but things got busy. You did an exquisite job - it is stunning! I was leery that the slices would come out as perfect as pictured in the issue - so glad to see they do!

    I'm not a huge fan of white chocolate either. In fact, today a coworker offered me a piece and I said no thanks. It just didn't appeal to me; it's not chocolate! A homemade whipped cream layer like you suggested would be fantastic!

    I think the most decadent dessert I've made is a Godiva chocolate cheesecake copycat from the cheesecake factory - flourless chocolate cake, chocolate cheesecake, chocolate mousse, covered in ganache.

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  5. I nearly drooled reading this post. Your cake looks BEAUTIFUL and I love it when a salesperson will go the extra mile to help make your day.

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  6. Will you please come and cook this for us. This looks amazing! BTW thanks for spelling out the truth behind white chocolate and your recent side suggestions.

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  7. Oh wow, the mousse cake is my favorite! This looks so good!

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  8. Your original question? Yes, I've seen something and had to make it immediately. It's 8:30 at night here. I have the springform pan but I don't have all the ingredients. I'm going to talk myself down from the ledge and wait until tomorrow to go to the grocery store...LOL

    This looks spectacular Megan!

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  9. OMG!!! that looks sooooo amazingly delicious. One of these days I think I might try it. I'm not a baker but it looks so good that I want to sink my teeth into it....LOL!!!!

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  10. Hahah your Williams-Sonoma story makes me laugh b/c I can see myself doing the exact same thing. I must say - you seemed to have done the recipe right! The cake looks perfect and makes me want to go in search of one of these pans :)

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  11. Definitely won't eat white chocolate on its own, but if it's paired with other things, the taste usually complements other ingredients. The homemade whipped cream swap is just as good!

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  12. Wow! This turned out beautiful! I love how defined the layers are...so pretty and I bet was delicious!

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  13. WOW. Does this ever look incredibly delicious!!! I will have to try it (and put my springform pans to more use than they currently get). :)

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  14. Wow, your photos are gorgeous! I'm drooling on my keyboard right now. This will be at the top of my "Must Try" recipe pile!

    Oh, and I'm totally with you on the white chocolate thing. While I was reading the recipe, I was thinking, "I wonder if I could make this with just whipped cream on top instead?" so it was great when I saw your comments on it further down!

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  15. Loving this cake. Great photos too!

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  16. Oh my gosh this cake is absolutely beautiful! Your photos are great as well!

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  17. Hi. I'm in love with that cake! Holy smokes! You see, those are the types of recipes I drool over, but then I get intimated by all those layers and steps. But then, I read a blog like yours and I get inspired. You really make it sound so easy. But I have a feeling my version would not come out as perfect as yours. Your version is flawless, right down to those perfect chocolate curls. Insane! A job well done!

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  18. did you save me a slice? Holy yum. and what a great story :)

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  19. I love mousse cakes-they're so light and fluffy. This one looks amazing!

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  20. M - This cake is spectacular, and your ambition and skills are impressive!

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  21. What a heavenly cake! It looks perfect - not a crumb out of place! I love white chocolate. I have a serious sweet tooth and it seems to satisfy it.

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  22. oh wow! the final product looks so professional!

    your boy friend's parents must love you even more now :)

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  23. Oh my word! Look at those layers! What an incredibly decadent dessert! I am such an idiot! My husband and I received those pans as a wedding gift but I didn't bake at the time and I sold them in a garage sale. What was I thinking???

    I prefer dark chocolate to white. My husband is just the opposite.

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  24. Oh, who could resist this! Nothing better than triple chocolate, especially when Ghirardelli's is involved!

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  25. I actually like white chocolate but only WITH regular chocolate, so basically I would love this mouse...yum

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  26. I'm glad I found out your blog from one of my local food blogger.

    This is cake I wanted to make for a while. You make it looks so simple. This is a great motivation that I should make one.

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  27. thats absolutely beautiful! you clearly mastered this recipe with your precision and skills. i love it! i haven't yet made a full-on cake yet, but it's something i need to try. nicely done!

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  28. OH... MY.... uncontrollable drooling... WOW!!!

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  29. Wow, just wow! It looks SO amazing!

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  30. I'm ready to fall over after a long day and now all I can think about is this chocolate mousse cake, especially layers 1 & 2. Add a bit of creme fraiche on top, and maybe I'll have to make this one soon, like tomorrow!

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  31. Megan..what do I think of white chocolate? I LOVE the stuff...especially in your beautiful, sinful, pie! I cannot stop looking at it, craving it..almost tasting it..and it's not even 9 am. That is a showstopper.

    As for the most decadent dessert I've ever made..there have been so many that..'butter, cream, chocolate, eggs and sugar' will be solidly chiseled into my gravestone (using that in one of my future blog entries lol)

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  32. Wow! So beautiful! Those are magazine pics! So creamy and light! Looks really yummy!

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  33. Thank you, thank you! You are all so sweet and so supportive! I hope you do make this cake... and then you'll have to come back and let me know what you think of it!

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  34. outstanding. this is elegant and amazing, and since i ADORE white chocolate, i'm pretty much smitten. your layers are perfect and i'm impressed...and famished. :)

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  35. While I'm not particularly fond of chocolate I have to say that is a most impressive looking dessert. Definitely one that would garner ooohs and aaahs.
    ~ingrid

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  36. Not sure what I did wrong but the white chocolate was the one part that didn't seem to want to melt correctly, I ended up heating it over a double boiler and then it almost looked like it got water in it (it didn't though.) Still tasted good but bugged me that it didn't appear to have enough warm liquid to melt all of the chocolate and it was the only part not silky smooth.

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  37. Hey Kevin, don't be too hard on yourself. White chocolate is tricky (because it's not real chocolate). You have to make sure to use white chocolate with cocoa butter in it. The feves I got worked well or the Ghirardelli bars are a good choice too. Ghirardelli chips never melt right and lesser quality white chips definitely won't work. Hope this helps!

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  38. Megan, I made this cake and took the liberty to modify it to suit the availability of ingredients locally. Mine does not look as ravishing as your's but it turned out fine

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  39. Megan ... the recipe absolutely ROCKS. I made this cake last night for a friends baby shower, and it was the only dish that got repeat visits and tons of compliments.

    I doubled the recipe and made it in a much larger square springform, so the cake wasn't as thick and gorgeous as yours but the taste was totally on point.

    I've been told that I'm going to be the designated cake maker for friends' birthday parties, etc.

    Thank you so much for sharing this ... amazing, amazing, amazing cake :)

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  40. Rockit - I'm so glad you enjoyed the cake. I can't believe you doubled it -- that's a lot of work!!

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  41. hey, omg this cake looks amazing i ust had to make one, im in the process of making one right now, the first layer is in the oven. but how do you transfer it to a wire rack if it still needs to be in the pan HELP!!!

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  42. Hi issy, just put the whole pan on a wire rack. Do not take the cake out of the pan.

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  43. Hi. I made this cake a few times and still have trouble getting the bottom layer to fill out to the sides of the springform pan. when it cools, it shrinks down (which is what i want) but the edges pull in too. when I remove the springform pan, the 2nd layer covers over the bottom layer so it looks like it isnt even there.

    What am I doing wrong?

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  44. Hi Michael - a couple things... my pan was 9 inches rather than 9.5 inches like the recipe says. I let the cake layer cool completely. And the 2nd layer should be thick enough that it shouldn't go down the sides. Spread it carefully, just over the cake. And remember, when you take the cake out of the pan, you can clean the sides with an offset spatula.

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  45. I'm not sure if it was the exact same cake but I made one really similar and it was fantastic. Yours looks taller then mine though.

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  46. What an absolutely wonderful cake, no piece of yummy art! I made this today for a small group of friends who couldn't get enough of it. So so good. Only difference was my mousse layers weren't thick enough because I used thick cream instead of whipping cream so the consistency wasn't as fluffy. Cake was still brilliant though. Thanks for sharing!

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  47. Hi young lady, Made the triple choc mousse cake n came out fantastic. Looks aside the taste was wonderful according to hubby and 2nd son. Thank you for posting the recipe.

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  48. I'm so happy to hear you enjoyed it!

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  49. I just made this cake!! Its in my fridge right now!!! :) thanks for the recipie I had to diviate just a little since i couldnt find the bar of chocolate the discs or the expresso powder, but so far so good!!! Thanks!!!

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  50. You're welcome! Enjoy!!

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  51. Hi Megan, today is my forth time I've have made this cake because it is soo good. I've been making this for my friends. My kids are waiting for me to make them another since I made this for the first time last thanksgiving. One more cake to go this football weekend for another friend before I make this for Valentines for the kids and hubby. Thanks again.

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  52. That makes me so happy! Enjoy!

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  53. I intend to try a few more recipes from your site.

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  54. I'm planning on making this cake for Valentines Day. Do you think I could use a 9" loose base cake tin instead of a springform?

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  55. I don't have any experience with loose base cake pans, but it looks like you have to slide the sides up over the cake? You could end up smudging the cake, so I would say a springform is better. But you could also clean the sides of the cake with an offset spatula, so it could work...

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  56. Thanks, thats what I thought! I've decided to use the springform I have but I don't think it's deep enough, did you have to get a deep springform pan or is yours quite a standard depth? Looking forward to making this cake so much, thanks for sharing. My hubby doesn't like white chocolate so I'm going to do the top layer with whipped cream. Yum!

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  57. Mine is standard. I think it's 2 1/2 or 3 inches deep. Whipped cream on top will be wonderful!

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  58. Thanks so much, I'm going to measure my sprinform tin right now!

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  59. good cake its for a birthday

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  60. A chocolate moused cake from Gayles Bakery in Ca. has been my son requested Bday cake for more years than I care to count.Three years ago we left the state and for my sons bray that year a friend delivered the cake to him.He has since moved to be closer to us but last year settled for a very poor imatation of Gayles cake..this year I decided to try to make something simular.Bicameral across your bologna while investigating and it sound so easy and looks fabulous. My only question being, instead of white chocolate layer teplacing that with a milk chocolate layer.making it the same only replacing bitter sweet chocolate with milk chocolate or semi sweet. Wish me luck!!!

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