Ingredients
1 ¾ cups all-purpose flour
¾ cup unsweetened cocoa powder
1 ½ teaspoons baking powder
1 ½ teaspoons baking soda
½ teaspoon salt
2 cups granulated sugar
2 large eggs
1 cup buttermilk (or 1 cup milk + 1 tbsp vinegar)
½ cup vegetable oil
2 teaspoons vanilla extract
1 cup hot coffee (or hot water for milder flavor)
For the Chocolate Mousse Filling:
1 ½ cups heavy whipping cream
1 cup semisweet chocolate chips or chopped chocolate
2 tablespoons powdered sugar
1 teaspoon vanilla extract
For the Chocolate Ganache Topping:
1 cup heavy cream
8 ounces semisweet chocolate, finely chopped
1 tablespoon butter (for shine)
👩🍳 Instructions
Make the Cake Layers:
Preheat oven to 350°F (175°C). Grease and line two 9-inch round cake pans with parchment paper.
In a large bowl, whisk together flour, cocoa, baking powder, baking soda, salt, and sugar.
Add eggs, buttermilk, oil, and vanilla. Beat until smooth.
Slowly mix in hot coffee until fully combined (the batter will be thin — that’s perfect!).
Divide batter evenly between pans and bake for 30–35 minutes, or until a toothpick comes out clean.
Cool cakes in pans for 10 minutes, then transfer to a wire rack to cool completely.
Make the Chocolate Mousse:
In a microwave-safe bowl, melt chocolate in 30-second bursts until smooth. Let cool slightly.
In a separate bowl, whip heavy cream, powdered sugar, and vanilla until soft peaks form.
Gently fold the melted chocolate into the whipped cream until smooth and fluffy.
Chill for 15–20 minutes before assembling.
Assemble the Cake:
Place one cake layer on a serving plate. Spread all of the chocolate mousse evenly over it.
Top with the second cake layer and gently press to set.
Chill the cake in the refrigerator for 30–60 minutes before topping with ganache.
Make the Ganache:
Heat heavy cream until just simmering, then pour over chopped chocolate.
Let sit for 2 minutes, then stir until smooth and glossy. Stir in butter.
Cool slightly, then pour over chilled cake, letting it drip beautifully down the sides.
🍰 Tips & Variations
Add crunch: Sprinkle a layer of crushed cookies or chopped hazelnuts between the cake and mousse.
Flavored twist: Add espresso powder, orange zest, or peppermint extract for a fun flavor boost.
Decorate: Top with chocolate curls, whipped cream, or fresh berries for an elegant finish.
Make-ahead: Assemble a day in advance and refrigerate — the mousse sets perfectly overnight.
🧊 Storage
Refrigerate: Cover and chill for up to 4 days.
Freeze: Wrap slices individually and freeze up to 1 month. Thaw in the fridge overnight before serving.
✨ The Ultimate Chocolate Celebration
This Chocolate Mousse Layer Cake is more than dessert — it’s an experience. Each bite delivers layers of moist cake, airy mousse, and rich ganache that melt in your mouth. Elegant enough for special occasions, yet simple enough to make anytime you crave something extraordinary.