Dark Chocolate Mousse Cake with a Cocoa Biscuit Base
Ingredients
For the Base:
1 cup | 100g cocoa biscuits, crushed
3 tbsp | 40g melted butter
Coffee or milk (optional, for soaking)
For the Filling:
1 cup | 180g dark chocolate
½ cup | 125ml milk
⅔ cup | 140ml sweetened whipping cream
For the Topping:
½ cup | 100g dark chocolate
½ cup | 130ml whipping cream
Step-by-Step Instructions
Step 1: Prepare the Base
Crush the biscuits: Start by crushing the cocoa biscuits until they turn into fine crumbs. You can do this using a food processor or by placing them in a sealed plastic bag and crushing them with a rolling pin.
Mix with butter: Transfer the crushed biscuits to a mixing bowl, and add the melted butter. Stir until the crumbs are well-coated and the texture is like wet sand.
Form the base: Press the biscuit mixture evenly into the base of a springform cake pan (around 7-8 inches in diameter). If you want extra flavor, lightly soak the base with some coffee or milk using a pastry brush. Refrigerate the base for about 15 minutes while you prepare the filling.
Step 2: Make the Chocolate Filling
Melt the chocolate: In a heatproof bowl, melt the dark chocolate over a pot of simmering water (double boiler method). Stir gently until smooth. You can also melt the chocolate in the microwave in 20-second intervals, stirring each time.
Warm the milk: In a separate saucepan, gently heat the milk until it’s warm but not boiling. Slowly pour the warm milk into the melted chocolate while stirring constantly. This ensures the chocolate stays smooth and glossy.
Whip the cream: In another bowl, whip the sweetened whipping cream until soft peaks form. Be careful not to over-whip, as this can cause the cream to become grainy.
Combine: Gently fold the whipped cream into the chocolate mixture using a spatula. Fold in small portions at a time to avoid deflating the mousse. Once combined, pour the chocolate mousse onto the chilled biscuit base and spread evenly. Refrigerate for at least 2 hours or until the mousse sets.
Step 3: Make the Topping
Prepare the ganache: In a small saucepan, heat the whipping cream until it just begins to simmer. Remove from heat and pour over the chopped dark chocolate in a heatproof bowl.
Mix until smooth: Allow the mixture to sit for 2 minutes to melt the chocolate. Then, stir until the ganache is smooth and glossy.
Top the cake: Once the mousse layer is firm, pour the ganache over the top of the cake, spreading it evenly with a spatula. Let it set for 20-30 minutes in the fridge.
Step 4: Serve
Once the ganache is set, remove the cake from the pan and slice to serve. Enjoy your decadent Dark Chocolate Mousse Cake!
Cooking Tips
Biscuit choice: You can use any type of cocoa-flavored biscuits, such as chocolate graham crackers or Oreos (without the filling). If you don’t have cocoa biscuits, plain graham crackers or digestive biscuits with a tablespoon of cocoa powder will work.
Folding technique: When folding the whipped cream into the chocolate mixture, be gentle to maintain the airy mousse texture. Use a figure-eight motion to fold.
Chill time: Make sure to give the mousse enough time to set, or else the layers may collapse. For the best texture, refrigerate the cake overnight.
Enhancing flavor: Add a tablespoon of espresso powder to the ganache to enhance the dark chocolate flavor.
Storage Tips
Refrigerator: Store the cake in an airtight container in the fridge for up to 3-4 days. The flavors deepen over time, making it even more delicious.
Freezer: You can freeze this cake for up to 1 month. Wrap it tightly in plastic wrap and store it in a freezer-safe container. Thaw in the refrigerator overnight before serving.