Triple Chocolate Mousse Cake
I have been tempted by Triple Chocolate Mousse Cake for well over three years now. I’ve seen a variety of recipes in a number of different places and have bookmarked it and doggy-eared it countless times. One day last week, my Chief Culinary Consultant mentioned that it had been awhile since I had made a big ol’ fancy cake. A show-stopper, as it were. Challenge accepted. I sifted through my notes, spreadsheets and cookbooks to see what I might want to bake up, when a page from a long-gone Cook’s Illustrated magazine fell out of a binder. The Triple Chocolate Mousse Cake. It was destiny.
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This triple layer cake is the trifecta of chocolate deliciousness. The bottom layer is a flourless chocolate cake… the middle layer is a light dark chocolate mousse… and the top layer is an even lighter white chocolate mousse. The combination of the three is rich, intensely flavorful and silky smooth. It’s a fabulous dessert to pair with coffee and enjoy slowly, lingering over each bite.
This cake is the holy grail for any chocolate lover. It takes a bit of time, but the assembly is relatively easy and absolutely, 100% worth it. You owe yourself this treat!
One year ago: Oatmeal-Raisin Ice Cream
Two years ago: How To Make a Rainbow Cake
Four years ago: Polenta Pizza
Triple Chocolate Mousse Cake
Ingredients
For the Bottom Layer
- 6 tablespoons unsalted butter, cut into 6 pieces, plus extra for greasing pan, (3 ounces )
- 7 ounces (198.45 g) bittersweet chocolate, finely chopped
- ¾ teaspoon (0.75 teaspoon) instant espresso powder
- 1½ teaspoons (1.5 teaspoons) vanilla extract
- 4 eggs, separated
- Pinch salt
- ⅓ cup (73.33 g) light brown sugar
For the Middle Layer:
- 2 tablespoons cocoa powder, preferably Dutch-processed
- 5 tablespoons hot water
- 7 ounces (198.45 g) bittersweet chocolate, finely chopped
- 1½ cups (357 ml) cold heavy cream
- 1 tablespoon granulated sugar
- ⅛ teaspoon (0.13 teaspoon) table salt
For the Top Layer
- ¾ teaspoon (0.75 teaspoon) powdered gelatin
- 1 tablespoon water
- 6 ounces (170.1 g) white chocolate chips, (1 cup )
- 1½ cups (357 ml) cold heavy cream
Instructions
- Make the Bottom Layer: Preheat oven to 325 degrees F. Butter the bottom and sides of a 9-inch springform pan that is at least 3 inches high.
- Melt the butter, chocolate and espresso powder in a large heatproof bowl set over a saucepan filled with 1 inch of barely simmering water, stirring occasionally until smooth. Remove from heat and cool for 5 minutes. Whisk in the vanilla and egg yolks; set aside.
- In a stand mixer fitted with the whisk attachment, beat the egg whites and salt at medium speed until frothy, about 30 seconds. Add half of the brown sugar and beat until combined, about 15 seconds. Add the remaining brown sugar and beat at high speed until soft peaks form when the whisk is lifted, about 1 minute longer, scraping down the sides halfway through. Whisk one-third of the beaten egg whites into the chocolate mixture. Using a rubber spatula, fold in the remaining egg whites until no white streaks remain. Carefully transfer the batter to the prepared springform pan, gently smoothing the top with an offset spatula.
- Bake until the cake has risen, is firm around the edges, and the center has just set but is still soft (the center of cake will spring back after pressing gently with your finger), 13 to 18 minutes. Transfer the pan to a wire rack to cool completely, about 1 hour. (The cake will collapse as it cools.) Do not remove the cake from the pan.
- Make the Middle Layer: Whisk together the cocoa powder and hot water in a small bowl and set aside. Melt the chocolate in a large heatproof bowl set over a saucepan filled with 1 inch of barely simmering water, stirring occasionally until smooth. Remove from heat and cool for 5 minutes.
- In the bowl of a stand mixer fitted with the whisk attachment, whip the cream, granulated sugar and salt on medium speed until the mixture begins to thicken, about 30 seconds. Increase the speed to high and whip until soft peaks form when the whisk is lifted, 15 to 60 seconds.
- Whisk the cocoa powder mixture into the melted chocolate until smooth. Whisk one-third of the whipped cream into the chocolate mixture to lighten. Using a rubber spatula, fold in the remaining whipped cream until no white streaks remain. Spoon the mousse into the springform pan over the cooled cake and gently tap the pan on counter 3 times to remove any large air bubbles; smooth the top with an offset spatula. Refrigerate for at least 15 minutes while preparing the top layer.
- Make the Top Layer: In a small bowl, sprinkle the gelatin over the water; let stand for at least 5 minutes. Place the white chocolate in a medium bowl. Bring ½ cup of the heavy cream to a simmer in a small saucepan over medium-high heat. Remove from heat and add the gelatin mixture, whisking until fully dissolved. Pour the cream mixture over the white chocolate chips and whisk until the chocolate is melted and the mixture is completely smooth. Cool to room temperature, stirring occasionally, 5 to 8 minutes (the mixture will thicken slightly).
- In the bowl of a stand mixer fitted with the whisk attachment, whip the remaining 1 cup heavy cream at medium speed until it begins to thicken, about 30 seconds. Increase the speed to high and whip until soft peaks form when the whisk is lifted, 15 to 60 seconds. Whisk one-third of the whipped cream into the white chocolate mixture to lighten. Using a rubber spatula, fold the remaining whipped cream into the white chocolate mixture until no white streaks remain. Spoon the white chocolate mousse into the pan over the middle layer. Smooth the top with an offset spatula. Return the cake to the refrigerator and chill until set, at least 2½ hours.
- The cake can be made up to 1 day in advance and refrigerated. Remove the cake from the refrigerator and let sit at room temperature for 45 minutes before releasing it from the pan. Garnish the top of cake with chocolate curls or dust with cocoa, if desired. Run a thin knife between the cake and side of the springform pan, then remove the side of pan. Cut into slices and serve. (For clean slices, dip a sharp knife into hot water and wipe dry between cuts.)
Notes
Did you make this recipe?
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Hi.. Is it ok to place some foil at the bottom of the pan before making the base? Because ill be making this on holiday and planning to transfer it into the cake box.
You could do that, although since there is a base to the springform pan, I’m not sure what difference it would make. Can’t hurt, though.
thanks
Hi, I’ve also been thinking of this cake for a long time…any ideas as to how it would transport? How long can it be left at room temperature, do you know? will it turn into a puddle if made and transported in any but wintery weather? thanks
Hi Rosalyn, It all depends on how long you have to travel. If you’re going an hour or less, I think it would be fine. Longer than that, and you might want to consider transporting it in a cooler. It won’t turn into a puddle, but you don’t want it to get too soft.
Does unsweetened cocoa powder work?
Hi Amy, Yes, you can substitute unsweetened cocoa powder, the flavor will just be a tad different.
Made today with unsweetened powder and was delicious!
errmm….can u pls show me the video?
I made this one today but not sure if I miss where the eggyolks and vanilla should be put, coz i think it is not mentioned where to put but just to set it aside. Anyway, I made a perfect one and my hubby loves it so much. Thanks Michelle.
Hi Vener, They are in step #2.
I’m planning on making this dessert on Thanksgiving. Do you think it would be possible to make the bottom layer (the cake layer) the day before and then make the other two layers the next day? I won’t have a lot of time to bake on Thanksgiving so I’m trying to do some of it the day before if possible. Thanks so much!
Hi Jessica, I think you could do that without a problem. Enjoy!
Dear Michelle, I urgently need your help: I decided to make this cake for my friend’s birthday which is tomorrow. I’ve just made the second layer and it turned out quite liquid (what I mean is that it does not have the usual, rather thick cream consistency). Have I done something wrong? Can I redeem it anyhow? Thanks in advance!
Hi Katherine, It should definitely be the consistency of thick whipped cream, at the very least. Unfortunately, I’m not sure what could have happened along the way, it’s so hard with all of the different variables that go into baking.
hey, I’m thinking of making this cake for a christmas potluck; its got such visual appeal I’m sure it’ll knock their socks off! =). I was wondering, where do you get your powdered gelatin? I’ve seen the squares before, do you know how many squares you would need for your recipe?
Hi Sarah, I buy the powdered gelatin in the baking aisle – the brand name is Knox. A box of it has four envelopes of powdered gelatin inside. I have never seen squares of gelatin, so I’m unsure of how much you would need :(
I agree with all of the comments. I originally found this recipe, too, in Cook’s Illustrated several years ago. It is most definitely my “go to” holiday recipe or when I just need a dessert that is off the charts and has a stunning presentation as well..
OH MY GOD! I made this cake for a visiting Aunt that is a self-proclaimed chocoholic. It took me 3 days….by choice…one for each layer, but it was the most amazing chocolate concoction that I have ever eaten. All you could hear at the table were OOO’s and AHHH’s. Will def make again! maybe for Christmas!
I just got down preparing this cake for my husband’s birthday today. In frig cooling as I type. Everything seemed to go smoothly until the whit chocolate layer. It seemed rather liquidy after folding in the whipped cream. Don’t know if I over whipped the cream. I did let chocolate mixture cool to room temp for 8 minutes, so I don’t think it was that. The Knox gelatine was freshly purchased so shouldn’t have been old. I whipped up some more heavy cream and added it to the mixture. It did “thicken up” a bit more, but now I’m kicking myself for doing that extra addition because it seems a little too airy. Maybe the liquidy white chocolate mixture would have hardened fine after the 2.5 hours of cooling. Oh well, we will see when I break it out after dinner tonight. I would be interested in hearing your comments on the consistency of the white chocolate layer after the whipped heavy cream is added. Many thanks!!!
Hi Susa, The white chocolate mousse layer was pretty much the same consistency as the regular chocolate mousse layer; they were not much different at all. I hope you still enjoy the cake!
Dear Michelle:
First, let me apologize for all the typos in my initial e-mail. Guess, I shouldn’t try to type such a long message via my iPhone. I didn’t even spell my name correct – yikes.
Second, and importantly, my husband (and I) absolutely loved the cake!!!!! He was really impressed and even bragged to his mother about it (yeah for me)! I am still not sure what happened to the white chocolate layer such that it was not initially the correct consistency, but adding the additional whipped heavy cream did not detract at all. The cake did not separate from the pan as smoothly as your picture looked but not too bad. I am excited to try this a second time to see if I can improve on the physical appearance. This really is a decadent cake and would be fabulous for the holidays.
Thank you,
Susan
I’ve just prepared it (all along the afternoon) and it was so worth it!! It’s the first time I make a fancy cake like this and it turned out amazing, thanks!!
hi :) I’m thinking of doing this for my special recipe in my cooking class. But the allotted time is only for 3 hours. Do you think I can make the base cake before hand? Also, I have no more time to practice this recipe. Do you have some tips so my mousse will be perfect like yours? :D thanks!
Hi Bea, Yes, you could make the base ahead of time. Best of luck to you!
Hi michelle,
This is absolutely gorgeous and I am considering making it for a friend’s birthday except there is one problem…she is allergic to eggs. Do you know of a good substitute? I’ve used applesauce before but I don’t think that would mesh well with chocolate mouse.
You’re right, I definitely wouldn’t go the applesauce route. Since the egg is only used in the flourless chocolate cake, and not either of the mousse mixtures, you might be able to get away with a substitution. I would ask your friend if there is an egg substitution she routinely uses in cakes or baked goods. Do keep in mind, however, that the egg whites need to be whipped and folded, which is an important part of the texture. So you would need to substitute for the yolks and the whites separately.
Michelle-
Instead of doing this last minute cake prep as you show (out of fridge 45 minutes early, then take out of pan when ready to serve), have you ever taken the cake out of pan several hours prior to serving it, plating it then and serving much later? Do you think that would work?
Hi Elana, I think you could do that without a problem at all.
I would like to do the same, put on cake plate then travel for about an hour. Would I need to refrigerate? Do you serve cold?
Hi Tracy, You would be okay transporting it an hour if it is already chilled. You should refrigerate it once at your destination if you won’t be eating it immediately.
Do you serve cold?
Yes.
One more question. I have not used that type of pan before. Do you leave the bottom of the pan on while you serve? I am assuming you just leave it.. Thanks!
Yes, you can leave the bottom in place for serving. Enjoy!
Omg I made this a couple years ago at Christmas. Cook’s Illustrated never disappoints. I love that you use a lot of their recipes. I know I can trust you as a cook! Keep up the great blog, Michelle! Oh, and Duke is so cute I wanna eat him up!!
One of the best cakes I have ever had added a thin crisp chocolate cookie layer under a cake similar to this one. The textural difference added a great deal to the cake. Even without that layer this looks great.
Hello Merlot
Did you add the thin crisp chocolate chip before or after baking?
Also did you put it before adding the cake mixture or on top of the cake? And which cookies did you use?
Jas
You’re killing me. 7 months pregnant & had to go dairy-free, ’cause anything animal dairy gives me coughing fits. And many woman who’ve been pregnant know what a coughing fit can do to other pregnancy side effects… (Ouch.)
This recipe was great timing, I had to make a choc mousse cake this weekend and I can tell you this recipe is a winner!! It was delicious, everybody loved it. Thanks Michelle!!!
Wonderful chocolate cake! If I could take a large bite right now…….:(
I absolutely love the look of this! Now I just need a special occasion to make it for! :-)
This sounds like it would take a but of time, but it seems so totally worth it. I would love to be eating this right now. It looks beautiful.
This looks amAZing!!! Going to have to try it soon!
I’ve been searching for a recipe for this for months, and I finally found it! Gorgeous! Thanks heaps for the recipe, can’t wait to try it!
I’ve had this one bookmarked for several years, too! Maybe it’s time to finally get around to making it…
Beautiful cake, this happens to be our absolute favorite! Love this recipe and love that its a Flourless cake. Would you mind if we make this cake and post it? Warmly, Anna and Liz
Sure! Enjoy!
This is a recipe that I just love. I made it for my daughter’s birthday when you first posted it. It was loved by all. The only changes I made was to use agar-agar for the mousse layers
Can you please tell me how you incorporated agar agar? What amount did you use for each layer?
I love that you accepted this challenge, this looks amazing!
I’m in trouble with this one as I absolutely HAVE to make this! Our local European Patisserie has a made this for years but I am Celiac and it is not an option as they use flour. Guess who is one happy little camper now with a recipe and 4 days off work to test it??? THanks!