Description

A decadent Triple Chocolate Mousse Cake featuring a moist chocolate sponge cake soaked in coffee syrup, layered with rich coffee-infused chocolate mousse, and topped with a smooth chocolate ganache. This recipe adds a nostalgic coffee twist to Fanny Lam’s original simple yet elegant chocolate mousse cake, perfect for dessert lovers seeking a sophisticated treat.

Ingredients

Chocolate Sponge Cake

1/2 cup (65g) all-purpose flour
2 tbsp cocoa powder
1/4 tsp salt
3 large eggs, room temperature
1/2 cup (113g) granulated sugar
1 tbsp oil
1/2 tsp vanilla extract

Coffee Soak for Baked Cake Layer

2 tbsp brewed coffee
2 tbsp simple syrup (made from 1/4 cup sugar and 1/4 cup water)

Chocolate Mousse

200 g bittersweet chocolate, finely chopped
1 tbsp butter
1/4 cup water, or coffee or coffee-flavored liqueur like Kahlua
3 eggs, separated
1 tbsp granulated sugar
1 cup heavy cream

Chocolate Ganache

100 g bittersweet chocolate, finely chopped
1/3 cup heavy whipping cream
1 tbsp Kahlua

Topping

Cocoa powder for dusting

Instructions

Prepare Chocolate Sponge: Preheat the oven to 325°F (163°C) and line an 8-inch cake pan with parchment paper without greasing the pan. In a bowl, sift together all-purpose flour, cocoa powder, and salt. Using a stand mixer, whip eggs and sugar until pale and forming ribbons when the whisk is lifted. Gently fold in the dry ingredients on low speed. Mix 1/3 cup of batter with oil and vanilla extract, then fold this mixture back into the main batter. Pour the batter into the pan and bake for 20-25 minutes until a tester comes out clean. Cool for 10 minutes in the pan before removing and cool completely on a wire rack.
Cut Cake and Prepare Coffee Soak: Once cooled, slice the cake horizontally into two thin discs. Fit the bottom cake layer into an 8-inch springform pan lined with acetate cake strips for easier release. Mix brewed coffee and simple syrup to use as a soak. Lightly brush the cut surfaces of the cake with this coffee soak to add moisture and coffee flavor.
Make Chocolate Mousse: Create a double boiler by placing a bowl over simmering water. Combine bittersweet chocolate, butter, and water or coffee or coffee liqueur in the bowl. Stir gently off heat until smooth and allow to cool slightly. Whip egg whites with sugar to medium peaks and set aside. In the same mixer bowl, whip the egg yolks until pale and fluffy, then slowly incorporate the cooled chocolate mixture. Fold the whipped egg whites into the chocolate mixture gently in three additions. Whip the heavy cream to soft peaks and fold it in last to create a smooth, airy mousse.
Assemble Mousse Cake: Pour the chocolate mousse over the soaked cake layer in the springform pan. Gently shimmy the pan to level the mousse surface. Refrigerate the assembly for several hours or overnight to allow the mousse to set firmly.
Prepare Chocolate Ganache: Heat heavy cream with Kahlua in a small pan until just about to simmer, then remove from heat. Add finely chopped bittersweet chocolate to the cream mixture and let sit for 3 minutes to soften. Stir gently until smooth and glossy. Pour the ganache evenly over the set mousse layer. Refrigerate for at least 10 minutes to allow the ganache to set well. Optionally, ganache can be prepared a day ahead for best flavor.
Finish and Serve: Carefully remove the acetate strips and springform pan sides. Dust the top of the cake lightly with cocoa powder before slicing and serving chilled.

Notes

Use room temperature eggs for more volume when whipped.
Make sure the chocolate mixture cools slightly before adding to eggs to prevent curdling.
Acetate cake strips help achieve neat edges and make cake removal easier.
The coffee soak enhances the chocolate flavor and adds moisture to the sponge layer.
Chill the mousse for at least 4 hours, preferably overnight, for best texture and flavor.
Ganache can be prepared a day ahead and refrigerated; bring to room temperature before pouring.
For coffee-flavored variation, substitute water in mousse with coffee or coffee liqueur.