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Dark Chocolate Mousse Cake Recipe

★★★★★

4.7 from 138 reviews
  • Author: Mariam
  • Total Time: 4 hours 30 minutes
  • Yield: One 4-layer 8 to 9-inch cake, serves 12-16 1x

Description

This Dark Chocolate Mousse Cake is a decadent layered dessert featuring moist, rich chocolate cake layers paired with luscious chocolate mousse and finished with a smooth chocolate ganache. Perfect for chocolate lovers, this cake combines a tender crumb, creamy mousse, and glossy ganache for a truly indulgent treat.

Ingredients

Scale

Cake Ingredients

  • 1 and 3/4 cups (219g) all-purpose flour (spooned & leveled)
  • 1 and 3/4 cups (350g) granulated sugar
  • 3/4 cup (64g) unsweetened natural cocoa powder
  • 2 teaspoons espresso powder (optional)
  • 2 teaspoons baking soda
  • 1 teaspoon baking powder
  • 1 teaspoon salt
  • 3/4 cup (180g) full-fat sour cream, at room temperature
  • 1/2 cup (113g/120ml) vegetable oil
  • 2 large eggs, at room temperature
  • 1/2 cup (120g/ml) buttermilk, at room temperature
  • 2 teaspoons pure vanilla extract
  • 1/2 cup (120g/ml) hot water or black coffee
  • 1 cup (170g) semi-sweet mini chocolate chips tossed in 1 Tbsp flour (optional)

Chocolate Mousse Ingredients

  • 1/2 cup (120g/ml) hot water
  • 1/4 cup (21g) unsweetened natural or Dutch-process cocoa powder
  • 8 ounces (226g) quality semi-sweet chocolate, finely chopped
  • 2 cups (480g/ml) heavy cream, cold
  • 2 Tablespoons confectioners’ sugar
  • 1/2 teaspoon pure vanilla extract

Chocolate Ganache Ingredients

  • 8 ounces (226g) quality semi-sweet chocolate, finely chopped
  • 1 cup (240g/ml) heavy cream

Optional Garnish

  • Fresh berries
  • Chocolate shavings

Instructions

  1. Preheat oven and prepare pans: Preheat your oven to 350°F (177°C). Grease four 8-inch or 9-inch cake pans, line them with parchment paper rounds, and grease the parchment to ensure the cakes release easily.
  2. Mix dry ingredients: In a large bowl, whisk together the flour, granulated sugar, cocoa powder, espresso powder (if using), baking soda, baking powder, and salt. Set aside.
  3. Combine wet ingredients: In another large bowl, using a mixer or whisk, blend the sour cream, vegetable oil, and eggs on medium-high speed until combined. Add the buttermilk and vanilla extract and mix until fully incorporated.
  4. Combine wet and dry ingredients: Pour the dry ingredients into the wet mixture, add the hot water or black coffee, and mix on low speed until just combined. Gently fold in the floured mini chocolate chips if using.
  5. Divide batter and bake: Evenly divide the batter among the prepared pans. Bake for 19-23 minutes, or until a toothpick inserted in the center comes out clean. Cool cakes in pans on a rack for 1 hour, then loosen edges, remove from pans, peel parchment, and cool completely on a rack. Expect slight sinking in the center.
  6. Prepare chocolate mousse base: In a small bowl, whisk together hot water and cocoa powder until smooth. Melt the chopped chocolate using a double boiler or microwave in 20-second increments, stirring until smooth. Stir the hot water/cocoa mixture into the melted chocolate until thickened and smooth; set aside.
  7. Whip cream and assemble mousse: Using a mixer with a whisk attachment, whip cold heavy cream, confectioners’ sugar, and vanilla extract on medium-high speed until medium peaks form (about 3 minutes). Gently fold the chocolate mixture into the whipped cream, being careful not to deflate it. Cover and refrigerate for at least 2 hours or up to 2 days.
  8. Level cakes and assemble layers: If needed, level the cake layers by slicing off any dome tops with a serrated knife to create flat surfaces. Place one cake layer on a cake stand or plate, spread about 1.5 cups (200g) of chocolate mousse evenly on top, then add the second layer upside down. Repeat frosting with mousse for the third layer right side up, then add the final layer. Spread remaining mousse over the top and sides for a crumb coat. Smooth using a bench scraper, then refrigerate for 1 to 4 hours.
  9. Prepare chocolate ganache: Place chopped chocolate in a medium heat-proof bowl. Heat heavy cream in a small saucepan over medium heat until it begins to simmer gently (no boiling). Pour warm cream over chocolate, let sit 2-3 minutes to soften chocolate, then stir slowly until smooth and glossy. Refrigerate ganache for 30 minutes to 1 hour to thicken.
  10. Apply ganache and garnish: Pour or spoon the thickened ganache over the chilled cake. Smooth the top and sides with an icing spatula. Garnish with fresh berries and/or chocolate shavings if desired. Serve immediately or chill uncovered for 4-6 hours before serving. The cake can be enjoyed chilled or at room temperature.
  11. Storage: Cover leftover cake tightly and refrigerate for up to 5 days for best freshness.

Notes

  • Use unsweetened natural cocoa powder for best results. Dutch-process cocoa can be used but may alter the flavor slightly.
  • Espresso powder is optional but enhances the chocolate flavor.
  • Buttermilk at room temperature ensures proper mixing and tender texture.
  • Hot coffee or hot water can be used to deepen the chocolate flavor; black coffee delivers more richness.
  • Flouring the mini chocolate chips prevents them from sinking to the bottom of the cake during baking.
  • Medium peaks in whipped cream are when peaks hold shape but the tips curl over slightly.
  • Ganache should not be overheated or boiled to avoid separation; gentle heat is key.
  • Prep Time: 30 minutes
  • Cook Time: 23 minutes
  • Category: Dessert
  • Method: Baking
  • Cuisine: American

Keywords: dark chocolate mousse cake, chocolate cake, chocolate mousse, chocolate ganache, layered cake, chocolate dessert

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Find it online: https://aromaofgrandma.com/dark-chocolate-mousse-cake-recipe/