Chocolate Mousse Cake

Prep Time: 90 mins | Cook Time: 40 mins | Course: Dessert | Serves: 16

Decadent dark chocolate mocha mousse cake with espresso powder, and topped with ganache. Inspired by Camila Hurst of Pies and Tacos https://www.piesandtacos.com/chocolate-mousse-cake/  

2 cups flour 

1 ¾ cups sugar 

½ cup unsweetened cocoa powder 

2 tsp baking soda

1 tsp baking powder

1 tsp salt

2 tsp instant espresso powder 

½ cup buttermilk 

½ cup sour cream 

½ cup olive oil

2 eggs 

1 Tbsp vanilla 

1 cup brewed coffee 

Mocha Mousse:

2 ½ cups dark chocolate chips 

4 eggs, divided 

2 tsp vanilla 

¼ tsp salt

1 Tbsp instant espresso powder 

2 Tbsp cold water

1 ½ tsp unflavored gelatin powder 

1 ½ cups heavy cream, divided

¼ tsp cream of tartar 

¼ cup sugar 

Mocha Ganache:

1 cup heavy cream

1 ½ cups dark chocolate chips

1 Tbsp instant espresso powder 

1 Tbsp honey, optional 

Preheat oven to 350°. Butter or spray oil to 9 inch cake pans and set to one side. Whisk flour, sugar, cocoa, baking soda, baking powder, salt, and espresso powder in a stand mixer bowl. In a large measurer or batter bowl, whisk buttermilk, sour cream, olive oil, eggs, vanilla, and coffee. Pour over the dry ingredients and stir on low speed until the batter is smooth. 

Divide better evenly into the prepared cake pans, and smooth the tops. Bake for 30-35 minutes. A toothpick tester should come out clean, and an insta-thermometer should read a minimum of 200*.

Melt chocolate chips in a microwave-safe bowl for 1 minute; stir until smooth. Add egg yolks, salt and vanilla stirring until incorporated. In a small bowl, sprinkle gelatin over cold water. Allow to bloom for 2 minutes. In a microwave-safe measuring cup or a bowl, heat ½ cup of the heavy cream for about 1 minute in the microwave. Stir in the bloomed gelatin and the espresso powder, stirring until smooth. Stir into the chocolate mixture until smooth. 

In a clean stand mixer bowl, whip egg whites until foamy. Add cream of tartar and continue to beat to stiff peaks. Gently fold half of the egg whites into the chocolate to lighten, taking care so the sir doesn’t get knocked out. Add the remaining egg whites, folding them in the same manner. 

Clean the stand mixing bowl and whisk attachment, and whip the remaining cup of heavy cream, adding sugar slowly, to stiff peaks. Fold the heavy cream gently into the chocolate mixture. 

When the cakes have cooled completely, and you are ready to fill and frost them, place one of the cakes in a 9-inch springform pan. Top with half of the mousse and place in the refrigerator. When the mousse has set, place the next cake layer on it and top with the remaining half of the mousse. You can smooth the top or mound it into a dome. Place in the refrigerator to chill. 

To make the ganache, microwave the heavy cream for 1 ½ minutes. Stir in the chocolate chips, espresso powder, and honey. Stir until smooth and let sit for one hour. The ganache will cool and thicken a bit. 

Remove the cake from the spring form pan when ready to assemble, and place it on a cake plate or serving platter. Spoon the ganache over the top, allowing it to drip down the sides decoratively. You might not use all of the ganache. Decorate with berries or chocolate curls as desired.