I must confess that, besides Thanksgiving, Christmas dinner is my favorite meal to plan, cook and serve. There are few times each year when I can take the time to prepare such a feast for family and friends, and I savor every moment.
Every year I challenge myself to create a dessert that’s truly memorable. This year I set out to make a chocolate layer cake — a bold choice, since working with layered cakes and mousses was new and somewhat intimidating to me.
I began testing recipes early in the fall. The first attempt was a disaster; I tucked that creation into the spare refrigerator and forgot about it for five days. The second try improved, but the white chocolate frosting was too sweet and the cake a bit heavy.
I didn’t give up. My goal was not merely a chocolate layer cake, but the lightest, most moist, intensely chocolate cake I could imagine — a real showstopper.
After two more attempts, I arrived at the cake I envisioned. Drawing on my French background, I created a dark chocolate génoise (sponge cake) brushed with a little coffee and Cognac for four layers. A silky milk chocolate mousse binds the layers, while a delicate white chocolate mousse covers the outside. Bittersweet chocolate curls finish the cake, adding another layer of chocolate flavor.
A holiday meal deserves a spectacular dessert — one that tastes as delightful as it looks.
Chocolate layer-mousse cake with Cognac and bittersweet chocolate curls
makes 1 large cake or serves 12
active time: 2 hours
For the cakes
- 1 1/4 cups unbleached all-purpose flour
- 1 cup Dutch-process cocoa, sifted
- 2 teaspoons baking powder
- 2 pinches sea salt
- 8 extra-large eggs, at room temperature
- 1 1/2 cups organic sugar
- 4 tablespoons unsalted butter, melted and slightly cooled
- 1 cup strong coffee, cooled to room temperature
- 1/3 cup Cognac
- 2 – 9″ non-stick round cake pans, lightly buttered and floured
For the milk chocolate mousse
- 9 oz (255 g) milk chocolate, coarsely chopped
- 1 1/2 cups heavy cream
- 1 tablespoon chocolate liqueur
- 1 teaspoon pure vanilla extract
For the white chocolate frosting
- 12 oz (340 g) white chocolate, coarsely chopped
- 1 1/2 cups heavy cream
- 2 oz (55 g) bittersweet chocolate, for garnish
- Preheat oven to 375°F (190°C).
- Step 1: In a medium bowl, whisk together the flour, cocoa, baking powder and salt. Set aside. In the bowl of an electric mixer, beat the eggs at high speed until very pale, thick and ribbon-like, about 2 minutes. Gradually add the sugar and continue beating until soft peaks form, about 1 more minute. Fold half the flour mixture into the whipped eggs gently. Fold in the melted butter, then fold in the remaining flour mixture, taking care not to overmix. Divide the batter evenly between the prepared pans. Bake 18–20 minutes, until the cakes have risen and a skewer inserted in the center comes out clean. Cool to room temperature before unmolding.
- Cook’s note: Cakes can be prepared up to 24 hours ahead. Cool, wrap in plastic and refrigerate. Bring to room temperature before assembling.
- Step 2: To make the milk chocolate mousse — Place the milk chocolate in a heatproof bowl and melt over simmering water, stirring until smooth. Remove from heat and let cool until just warm. In the mixer bowl, whip the heavy cream with the chocolate liqueur and vanilla at medium speed until thick but not overbeaten. Fold the melted milk chocolate into the whipped cream until well combined. Transfer to a container, cover and refrigerate 2–4 hours to firm up.
- Step 3: To make the white chocolate frosting — Melt the white chocolate in a heatproof bowl over simmering water, stirring until smooth. Remove from heat and cool until just warm. Whip the heavy cream at medium speed until thick. Fold the melted white chocolate into the whipped cream until smooth. Transfer to a container, cover and refrigerate 2–4 hours.
- Step 4: To assemble the cake — Unmold the cakes and, using a cake leveler or a serrated knife, cut into four even layers about 1″ thick. Place one layer on the serving platter and line the rim of the platter with plastic wrap to keep it clean while frosting. Using a pastry brush, soak the cake layer with one quarter of the coffee and Cognac. Spread one-third of the milk chocolate mousse evenly over the layer. Repeat with two more layers, each soaked and filled, then top with the last cake layer and brush with the remaining coffee and Cognac. Spread the white chocolate frosting across the top and then the sides, reserving a little for piping a decorative rim if desired. Remove the plastic wrap from the platter and pipe frosting around the base. Loosely cover and refrigerate 4–6 hours. Remove from the refrigerator 30 minutes before serving. Just before serving, shave the bittersweet chocolate with a vegetable peeler to make curls and scatter them over the cake and platter rim.
Viviane’s tip
- This cake requires time and planning, but much can be done ahead. The chocolate génoise can be made a day in advance, and the assembled cake should be chilled 4–6 hours before serving. With a little preparation, the result is well worth the effort — if I can make it, anyone can.