Yesterday, we celebrated Jeffrey’s birthday. I catered a large lunch so I knew a big home cooked meal was not an option, but an absolutely fabulous dessert was a must. I scheduled my week in a way that I could accomplish all the tasks for my catering job as well as have enough time to make Jeffrey’s birthday cake and a few treats throughout the week.

By the time Thursday night rolled around, I was very happy to go out to eat; my busy week had finally caught up with me and I was beyond tired. We enjoyed a nice meal out and gladly refused every offer for dessert because we had Triple Chocolate Mousse Cake waiting for us in the fridge at home. I was a little nervous as I was removing side of the springform pan to reveal the dessert but as soon as I saw the dessert my worries quickly left me. It turned out incredible and any chocolate lover will be sure to enjoy this cake. It is three layers of chocolate perfection. The bottom layer is similar to a flourless chocolate cake, the middle is a chocolate mousse and the top is an elegant white chocolate mousse. When you put it all together, it is heaven!

The cake does require time and patience but it is totally worth the effort for a special occasion especially if you are a chocolate lover like Jeffrey.

Triple Chocolate Mousse Cake garnished with grated chocolate.

Triple Chocolate Mousse Cake

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Ingredients:
For the bottom layer:
6 tablespoons unsalted butter, cut into 6 pieces (plus extra for greasing the pan)
7 ounces bittersweet chocolate, finely chopped
3/4 teaspoon instant espresso powder
1 1/2 teaspoons vanilla extract
4 large eggs, separated
pinch of salt
1/3 cup packed light brown sugar

For the middle layer:
2 tablespoons cocoa powder, (I used a Dutch-processed cocoa)
5 tablespoons hot water
7 ounces bittersweet chocolate, finely chopped
1 1/2 cups heavy cream
1 tablespoon granulated sugar
pinch of salt

For the top layer:
3/4 teaspoon powdered gelatin
1 tablespoon water
6 ounces white chocolate, finely chopped
1 1/2 cups heavy cream

For garnish:
grated chocolate or cocoa powder

Directions:

Bottom Layer
To make the bottom layer, butter the bottom and sides of a 9-inch springform pan. (I also lined the bottom of the pan with parchment and then buttered the parchment as well for easy removal.) Preheat the oven to 325 degrees making sure the oven rack is in the center position of the oven. Combine the butter, chocolate, and espresso powder in a large heatproof bowl set over simmering water. Stir occasionally until the mixture is smooth. Remove from heat and let cool for about 5 minutes. Once it has cooled whisk in the vanilla and egg yolks. Set aside.

In a stand mixer fitted with the whisk attachment, beat the egg whites and salt on medium speed until foamy, about 30 seconds. Crumble half of the brown sugar into the mixing bowl. Beat until incorporated, about 15 seconds. Add the remaining brown sugar and continue to beat on high speed until stiff peaks form. Once the stiff peaks form, use a whisk and mix one-third of the beaten egg whites into the chocolate mixture. Fold in the remaining egg whites gently with a rubber spatula until no streaks remain. Pour the batter into the prepared springform pan and smooth the top.

Bake until the cake has risen, is firm around the edges and the center has just set but is still soft (it should spring back after pressing gently with a finger), about 14-18 minutes. Transfer the cake to a wire rack to cool completely, at least 1 hour. Do not remove the cake from the pan. (If not making the second layer right away, cover with plastic wrap and refrigerate until ready to proceed.)

Second Layer
To make the second layer, whisk together the cocoa powder and hot water in a small bowl; set aside. Melt the chocolate in a heatproof bowl set over simmering water, stirring occasionally until smooth. Once melted, remove from the heat and let cool slightly, 2-5 minutes.

In the clean bowl of a stand mixer fitted with the whisk attachment, whip the cream, 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. Add the cocoa powder mixture and whisk until smooth. Using a whisk, mix one-third of the whipped cream to the chocolate mixture. Fold in the remaining whipped cream gently with a rubber spatula until no streaks remain. Pour the mousse into the springform pan over the cooled cake. Gently smooth the top with a spatula. Refrigerate for at least 15 minutes while preparing the top layer.

Top Layer
To make the top layer, sprinkle the gelatin over the water in a small bowl and let stand at least 5 minutes to soften. Place the white chocolate in a medium sized bowl. Bring 1/2 cup of the cream to a boil in a small saucepan. Remove the pan from the heat, add the gelatin mixture and stir until dissolved. Pour the hot cream mixture over the white chocolate and let stand about 1 minute. Whisk until the mixture is smooth. Cool to room temperature, about 5-8 minutes, stirring occasionally.

Using a stand mixer fitted with the whisk attachment, whip the remaining 1 cup of cream at medium speed until it begins to thicken. Increase the speed to high and whit until soft peaks form when the whisk is lifted. Using a whisk, mix one-third of the whipped cream into the white chocolate mixture. Fold in the remaining whipped cream gently with a rubber spatula until no 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 until set, at least 2 1/2 hours. Once the cake has set you may cover with plastic wrap. (I left mine uncovered in the refrigerator over night and then covered it once I had cut the cake.)

When ready to serve, remove the sides of the springform pan, using a knife to go along the sides. Garnish with grated chocolate or cocoa powder.

Adapted from Cook’s Illustrated