Triple Chocolate Mousse Cake, ethereally light
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Who wants cake? This triple chocolate mousse cake isn't just any old cake.
It's a special occasion cake.
It's a takes-three-days-to-make cake.
It's a hunt-down-three-or-four-kinds-of-chocolate cake.
It's a reorganize-the-freezer-to-make-this-thing-sit-level-overnight cake. It's, let me just say, a totally-worth-it cake.
I made this for my sister Erin's birthday. She was having a low key party at her place, and I offered to bring a dessert. When I asked her what she wanted, she gave me carte blanche.
When left to my own devices, I have a tendency to go overboard when I'm making something for someone else.
My ambition sometimes overmatches my time and basic sense of reason.
It probably says something about me that when I scanned the recipe and saw instructions that said "at least two days ahead of time" I thought, "that seems reasonable." Really with this cake, I was showing restraint.
This comes from Joanne Chang's second cookbook, Flour, Too (her first one is, not surprisingly, named Flour).
Both of her books are named for and feature recipes from her Boston cafe and bakery, Flour. The first book focused exclusively on sweets, but this one looks to be about evenly divided between sweets and savories.
It doesn't just have recipes for special occasion desserts, it has plenty of simple breakfast baked goods and light cafe fare that's appropriate for everyday.
In the headnote to this recipe, Chang mentions that this cake is a personal favorite, even though she isn't a chocolate fiend. I can see why.
With three layers of mousse, four layers of flourless chocolate souffle cake, all topped with a layer of bittersweet ganache, this cake sounds like it would be unimaginably rich and intensely chocolatey.
But this cake is surprisingly, ethereally light. I kind of want to call it a triple chocolate cloud cake.
The white, milk, and bittersweet chocolate mousses don't just look pretty, they also balance each others' sweetness and bitterness beautifully.
It actually makes me wonder why we don't see more desserts take advantage of this chocolate trio.
I mostly followed Chang's recipe. The one significant change I made was to the white chocolate mousse. She uses a vanilla bean to flavor the mousse, but I opted to swap in fennel seeds, which I think are just fantastic here.
(Hear me out, fennel infused in cream is something magical and subtle and works almost like vanilla bean here but is way cheaper.)
I wouldn't call myself a big white chocolate fan, but I could have eaten a bowl of this white chocolate fennel mousse. Erin remarked that she really liked it too.
It's worth noting that these are more chocolate whipped creams than true mousses, so maybe we shouldn't be eating them by the bowl full, but each of them--the white chocolate fennel mousse, the milk chocolate coffee mousse, and the bittersweet chocolate mousse--is so good that if you're not licking the beater after you whip these, I'm pretty sure you're doing it wrong.
It does take three days to make this cake, but most of the work is on the second day.
The first day you make the mousse bases, which involves scalding the cream and pouring it over chopped chocolate and then refrigerating it overnight.
The second day you make the cake and the soaking syrup, whip the mousses, assemble the cake and put it into the freezer overnight. The third day you trim the cake, and make and top the cake with ganache.
It is quite a bit of work, but it's doable even if you're not quite as insane as I am.
Looking for other absurdly complicated cakes? Try this brown butter cranberry curd cake with Biscoff frosting, this strawberry fraisier with Lillet chiffon cake, this passion fruit lime bavarian, or this s'mores cake with toasted marshmallow meringue frosting.
Triple Chocolate Mousse Cake
This cake sounds decadent, but when you eat it, it feels incredibly light. It’s a project. It needs to be started at least two days before you want to serve it. It’s totally worth all of the work. I think this is one of the best desserts I’ve ever made. It’s worth using good quality chocolate here. I used Guittard for the milk and dark chocolates because that’s what I had on hand and Ghiradelli for the white chocolate because that’s what I could find at the grocery store. The coffee flavor is very mild in the finished cake. It serves to deepen the chocolate flavor rather than stand out on its own. This makes a big cake. If you aren’t feeding a crowd, you can cut the frozen cake in two and store half of it, well wrapped, in the freezer for another time. I probably could have done that with this one.
Ingredients
White Chocolate Fennel Mousse
- 1 ½ cups (360 ml) heavy cream
- ¾ teaspoon fennel seed
- 3 ounces (85 g) white chocolate, chopped
- ⅛ teaspoon salt
Milk Chocolate Coffee Mousse
- 1 ½ cups (360 ml) heavy cream
- 1 teaspoon ground coffee
- 3 ounces (85 g) milk chocolate, chopped
- ⅛ teaspoon salt
Bittersweet Chocolate Mousse
- 1 ½ cups (360 ml) heavy cream
- 3 ounces (85 g) bittersweet chocolate, chopped, I used 72% cacao
- ⅛ teaspoon salt
Chocolate Souffle Cake
- 10 large eggs, separated
- ¼ cup (60 ml) brewed coffee at room temperature
- 10 ounces (280 g) semisweet or bittersweet chocolate, melted and cooled, I used 72% cacao
- ¼ teaspoon salt
- 1 ¼ cups (250 g) granulated sugar
Cake-Soaking Syrup
- ½ cup (120 ml) hot brewed coffee
- 6 tablespoons (75 g) granulated sugar
Ganache
- 4 ounces (115 g) semisweet or bittersweet chocolate, chopped, 56% to 62% cacao
- ½ cup (120 ml) heavy cream
Instructions
At least 2 days in advance:
- Make the three mousse bases.
- Start with the white chocolate. Heat the cream and fennel seeds in a heavy bottomed medium saucepan. Put the chopped white chocolate in a medium heat proof bowl and have a fine mesh strainer ready. Heat the cream just until bubbles form around the edges. Immediately pour over the white chocolate. Let it stand for about two minutes to melt the chocolate, then stir until the chocolate is thoroughly melted.
- Pour through a fine mesh strainer to remove the fennel seeds, add the salt and transfer the mixture to a small storage container.
- Repeat with the milk chocolate mousse, heating the cream with the ground coffee (pass it through a strainer, but don’t worry if some of the finer ground coffee slip through).
- Then repeat with the bittersweet chocolate mousse, heating the cream on its own this time. (No real need to strain this one.) Store in the refrigerator overnight (can be made several days in advance).
At least 1 day in advance:
- Make the soaking syrup. Brew ¾ cup of coffee. Use ½ cup hot here and reserve ¼ cup at room temperature for the cake. Mix ½ cup (120 ml) coffee with 6 tablespoons (75 g) of sugar and stir until the sugar is dissolved.
- Make the cake. Preheat the oven to 350° F and place one rack in the center and one in the top third of the oven. Line two 13″ x 18″ rimmed baking sheets (half sheet pans) with parchment paper and spray with nonstick baking spray (if you’re making this gluten free, don’t use the baking spray that has flour mixed into it).
- In a large bowl, whisk together the egg yolks, remaining coffee, melted chocolate and salt. In the bowl of a stand mixer fitted with a whisk attachment, add the egg whites and beat on medium speed for about 2-3 minutes until soft peaks form. The tines of the whisk should leave a trail in the whites and when you lift the head of the mixer the whites should should peak and droop. With the mixer on medium, add the sugar slooowly, about a tablespoon at a time, until it’s all added. This process should take about 2 minutes. Increase the speed to medium-high and beat until the whites are glossy and smooth and hold their peaks.
- Using a rubber spatula, fold about one-third of the whites into the chocolate-yolk mixture to lighten it. Then gently fold in the rest of the whites until no white streaks remain. Do this carefully. Egg whites are easy to deflate.
- Divide the batter between the two prepared sheet pans. Starting at the corners, spread the batter evenly over the pan with an offset spatula. It doesn’t need to be perfectly smooth, but you want the corners and edges filled in. The batter should be about a ½ inch (1 cm) deep.
- Bake the cakes, rotating the pans from front to back and switching between the racks about halfway through, about 16-18 minutes. The cakes should look dry on top and when you touch it with a finger, the top should feel dry and delicate and almost shatter and the cake below should feel moist (Chang says the cake top should be “crispy”). Let the cakes cool on wire racks for 10 minutes. At this point you can assemble the cake or wrap the cakes (still in their pans) with plastic wrap and keep at room temperature for one day.
- Assemble the cake. Run a paring knife around the edge of the pan to release the cake from the sides of the pan. Using a very sharp knife (or kitchen shears) cut each cake in half–from the middle of one long side to the other–cutting through the parchment. You want to have four layers of cake, each about 8″x12″. Cut a piece of cardboard so it’s slightly larger than the cake (you don’t need much overhang here–I probably had too much in the photos above).
- Take one cake layer with the parchment attached and carefully flip it over onto the cardboard and remove the parchment. If the cake breaks anywhere, don’t worry, just patch it together as best you can and keep going. In the bowl of stand mixer fitted with a whisk attachment, add the white chocolate fennel mousse and whip until it holds stiff peaks.
- Spread the mousse evenly over the cake layer with an offset spatula. You want an even layer, but you don’t need to worry about some of it spilling over the sides because you’ll trim the edges later.
- Clean and dry the mixing bowl and the whisk attachment. Take another cake layer with the parchment and carefully flip it over onto the white chocolate mousse and remove the parchment.
- Using a pastry brush, spread about a third of the soaking syrup over the cake layer.
- Whip the milk chocolate mousse until it holds stiff peaks. Spread it in an even layer over the cake.
- Again, clean and dry the mixing bowl and whisk attachment.
- Take another cake layer with parchment, flip it over onto the milk chocolate mousse, and remove the parchment.
- Brush about half of the remaining soaking syrup onto this cake layer.
- Whip the bittersweet chocolate mousse until it holds stiff peaks. Spread it in an even layer over the cake.
- Take the last cake layer with parchment and carefully flip it over onto the bittersweet chocolate mousse. Brush with the remaining soaking syrup.
- At this point, make sure that you have an even landing spot for the cake in the freezer. Wrap the cake gently with plastic wrap and put it in the freezer overnight. Depending on how stiff your cardboard is, you might want to place a sheet pan underneath it to make this easier and to keep the cake even.
About 4-5 hours ahead of serving:
- Remove the cake from the freezer and place on a cutting board. Using a sharp chefs knife dipped in hot water trim about a ½ inch (1 cm) from each side of the cake, dipping and wiping the knife clean between cuts, to expose the even layers of mousse. (You can snack on these trimmings later–they’re best after they thaw.) Trim the cardboard base so it is flush with the cake and set on a wire rack set over wax paper.
- Make the ganache. Place the chopped chocolate in a small heatproof bowl. With this small amount of cream, it helps to partially melt the chocolate before you add the cream. You can heat it in 15 second bursts in the microwave or heat it over a double boiler until it’s about half melted.
- Heat the cream in a small saucepan until bubble form around the edges. Pour over the chocolate and let sit for about 30 seconds.
- Starting in the center and working out to the edges of the bowl, slowly whisk the chocolate and cream together until the chocolate is fully melted and the mixture is uniform and smooth.
- Pour the ganache over the cake and quickly spread in an even layer with an offset spatula, letting the excess drip down the sides of the cake. The sides should remain mostly exposed to show off the mousse layers. At this point, you can top with chocolate shavings or just leave the ganache as is. Store in the refrigerator until you’re ready to serve it.
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Nordic Ware Natural Aluminum Commercial Baker's Half Sheet (2 Pack), Silver
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Baking Parchment Paper - Set of 100 Half-Sheets
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Ghirardelli Premium Baking Bar, White Chocolate, 4 Ounce (Pack of 12)
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Coucher du Soleil 72% Cacao 16 oz by Guittard
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Tcho Chocolate Milk Chocolate Bar - Classic - Case of 12 - 2.5 oz.
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KitchenAid KP26M1XNP 6 Qt. Professional 600 Series Bowl-Lift Stand Mixer - Nickel Pearl
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Cuisinart CTG-00-3MS Set of 3 Fine Mesh Stainless Steel Strainers
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Ateco Ultra Offset Spatula 3 Piece Set; Top Sellers 1305 - 4.25 Inch, 1307 - 7.75 Inch, and 1309 - 9.75 Inch, Stainless Steel Blades
Nutrition Information:
Yield:
12Serving Size:
1Amount Per Serving: Calories: 843Total Fat: 65gSaturated Fat: 40gTrans Fat: 1gUnsaturated Fat: 21gCholesterol: 271mgSodium: 216mgCarbohydrates: 51gFiber: 7gSugar: 38gProtein: 15g
Totally worth it is right! This was so delicious.
Gorgeous layer cake! Never thought of using fennel seed in a sweet dessert. How interesting! I am sure it tastes incredible. It is not an easy cake, but I will do anything for a chocolate cake. Sharing of course! Btw, I hope you eat up all those cake scraps. 😉
Thanks! I love the way that fennel seed plays with the white chocolate here. I know it's a little unusual, but I think it really works. (And the scraps were, indeed, delicious...)
oh yes... this is my kind of dessert!! Mousse, cake..triple chocolate... yes.. hand me a fork and I"m done. 🙂 Yum! It really is gorgeous. 🙂
Thanks 🙂
This is one gorgeous cake!!!! Worth all the work!!! What a lovely recipe and pics...I bet it was delicious too...wish I can have a piece hehehehe..my addiction to chocolate...
Thanks, Manal! It's one of the best cakes I've ever made.
This is a beautiful cake. Love all the layers. A lot of work but worth it.
Thanks, Peter! It's a special cake.
I love this! An awesome celebration of all things chocolate, and those layers are so elegant. Pinning this for later!
Thanks, Rachel! I love this cake.
Such a beautifully layered, delicious cake! (Love the step-by-step images, too.) 🙂
Thanks! I always feel like a picture conveys so much about the process of a project like this.
This reminds me of my wedding cake ... as she squeals with delight! I'm bookmarking the recipe to make for a special occasion - our anniversary next summer. Although if I keep looking at these photos, I may be making it sooner.
Thanks, Linda! This is totally worthy of a special occasion!
What a wonderful idea to add fennel seeds to the white chocolate mousse. Sounds lovely, and this looks like a beautiful cake!
Thanks, Amanda! I love that combination. It's one of my favorite cakes ever.
This cake looks worth it's every bit of dedication it takes to make it! What a wonderful treat for a special occasion, or just to treat yourself! Thank you for sharing, going on my list of must make! X
Thanks, Adriana! It's so worth the effort.
Ummm...I need this right now! It looks so yummy...love the addition of fennel too...sounds so interesting
Thanks, Wajeeha! I think the flavor combinations here really work.
Wow, I love how you included all the steps here, this gives me the confidence that I could actually attempt this gorgeous recipe! My father in law and hubby would love it! (and me too!)
Thanks, Sara! I won't lie and tell you this is easy, BUT it is totally manageable if you break it down into separate parts. I always feel that visuals really help me when I'm entering into unknown baking territory.
Hi! When you say heavy cream for the mousses, do you actually mean heavy WHIPPING cream? And not actually heavy cream?
Because I used heavy cream for the dark chocolate mousse. But then used heavy whipping cream for the milk chocolate and white chocolate. The milk and white cream whipped beautifully. But the dark chocolate just turned to ganache and would not whip.
I used 72% dark chocolate for the dark chocolate mousse, semi-sweet morsels for the milk chocolate mousse, and Lindt white chocolate for the white mousse.
Both heavy cream and whipping cream work for this. Heavy cream and heavy whipping cream are the same thing; whipping cream is slightly lower in fat but works basically the same way. I'm not sure why your dark chocolate mousse wouldn't whip.
How did you keep the chocolate/yolk mix soft and creamy? Mine solidified as I was whipping the egg whites 🙁
Hmm...I'm not sure what happened. My best guess is that everything got a little too cold (if your kitchen is cold, like mine is these days, that seems possible). You could warm it gently--set the bowl on a heating pad or in a pan of hot water and give it a stir until everything loosens up.
If you are working in a cold kitchen, it's a good idea to bring the eggs up to room temperature for a recipe like this so they aren't refrigerator-cold. You can set them in a bowl of warm water for about 10 minutes to speed up that process.
Can the cake be frozen for a few days?
Yes, absolutely, but I'd give it an extra layer of plastic wrap for extra protection. Just be sure to do the final steps (trimming the edges and covering with ganache) within 24 hours of serving it.
Hi! It’s an amazing recipe, thank you so much! Planning to make this for a friend’s bday!
Quick question - why is it important to put the cake in the freezer at the last of second day? Can i just keep it in the fridge to set and then remove the edges and add the glaze during the last day?
Freezing the cake is essential for making it firm enough to trim cleanly. It's also essential for getting the ganache to set quickly, which helps to structure the cake. This is a big project where the details matter. Good luck!
@Mary Kasprzak,
Thanks a lot for the response Mary!
Also is there any chance of making the flourless chocolate cake eggless?
Making this without eggs would be a huge change because they make up the bulk of the batter. It's probably possible to make a version with aquafaba, but I haven't tested anything like that and I'm not sure what the conversion would be. You might try searching for a vegan chocolate souffle cake to substitute here. I don't have much experience with egg substitutes.
Hello! I’ve made this recipe once and it was amazing! This time i want to make in the form of a traditional round layered cake. Meaning a sponge then dark chocolate mousse, again a sponge then milk chocolate mousse so on so forth.
Any idea how can i bring my thoughts to reality?
I’m making this cake for my husband’s birthday and want to decorate it as custom cake from outside using buttercream.
Would really appreciate your help here:)