Black Tie Mousse Cake

**For the Ganache**:
– 1/2 cup heavy cream
– 4 ounces semi-sweet chocolate

**Optional Garnish**:
– Whipped cream
– Fresh berries (like raspberries or strawberries)
– Shaved chocolate or cocoa powder

### How to Make Black Tie Mousse Cake

#### Step 1: Make the Chocolate Cake Base
1. Preheat your oven to 350°F (175°C) and grease a 9-inch springform pan.
2. In a large bowl, sift together the flour, sugar, cocoa powder, baking powder, baking soda, and salt.
3. Add the milk, vegetable oil, egg, and vanilla extract. Mix until smooth.
4. Gradually add the boiling water, mixing until the batter is well combined. The batter will be thin, but that’s okay!
5. Pour the batter into the prepared pan and bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
6. Let the cake cool completely in the pan before removing the sides.

#### Step 2: Prepare the Chocolate Mousse
1. In a heatproof bowl, melt the semi-sweet chocolate in a double boiler or microwave, stirring until smooth. Set aside to cool slightly.
2. In a separate bowl, beat the heavy cream and vanilla extract until stiff peaks form.
3. Gently fold the melted chocolate into the whipped cream until combined. Set the mousse aside.

#### Step 3: Prepare the White Chocolate Mousse
1. In a heatproof bowl, melt the white chocolate in a double boiler or microwave, stirring until smooth. Let it cool to room temperature.
2. In a separate bowl, beat the heavy cream and vanilla extract until stiff peaks form.
3. Fold the melted white chocolate into the whipped cream, blending gently until smooth. Set aside.

#### Step 4: Assemble the Cake
1. Once the chocolate cake has cooled, carefully slice it into two even layers.
2. Place the bottom layer of the cake in the center of the springform pan (you can line the pan with parchment paper for easy removal).
3. Spread a layer of chocolate mousse evenly over the cake layer.
4. Add the second cake layer on top of the mousse and gently press down.
5. Spread a layer of white chocolate mousse over the second cake layer, smoothing it out to the edges.

#### Step 5: Make the Ganache
1. In a small saucepan, heat the heavy cream until it begins to simmer (don’t let it boil).
2. Remove from heat and pour over the chopped semi-sweet chocolate. Stir until smooth and glossy.
3. Allow the ganache to cool slightly before pouring it over the top of the cake, allowing it to drip down the sides.

#### Step 6: Refrigerate and Serve
1. Refrigerate the assembled cake for at least 4 hours, or preferably overnight, to allow the mousse to set.
2. Before serving, garnish with whipped cream, fresh berries, and shaved chocolate if desired.
3. Slice carefully and enjoy this indulgent treat!

### Tips for Success
– **Be patient**: Allow the cake to fully cool before assembling the layers, and refrigerate the finished cake to ensure the mousse sets properly.
– **Custom flavors**: Feel free to experiment by adding a splash of liqueur like Grand Marnier or Baileys Irish Cream to the mousse layers for an added depth of flavor.
– **Make ahead**: This cake can be made a day in advance, making it perfect for parties and gatherings.

### Conclusion

Black Tie Mousse Cake is the perfect dessert for anyone who appreciates the finer things in life. With its decadent layers of chocolate cake, rich chocolate mousse, smooth white chocolate mousse, and glossy ganache, this cake will elevate any special occasion. Whether it’s a birthday, holiday, or simply a well-deserved treat, this cake will wow your guests and leave them wanting more. So, roll up your sleeves and create this luxurious dessert that’s sure to be a crowd favorite!