Dark Chocolate Raspberry Truffle Layer Cake
Three-layer dark chocolate cake with espresso notes, filled with raspberry sauce and chocolate ganache, frosted with raspberry buttercream, and finished with a chocolate glaze. The combination of cocoa and espresso powder deepens chocolate flavor, while fresh raspberries and tart lemon juice brighten each layer. A showstopper dessert requiring advance preparation.
Ingredients
- 1 ½ cup unsweetened cocoa powder
- 1 tbsp. coffee or espresso powderinstant espresso powder1:1flavor
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- 1 ½ cup boiling water
- ¾ cup sour cream
- 1 tbsp. vanilla extract
- 3 stick unsalted butter, at room temperature
- 2 ½ cup plus 2 tbsp. sugar
- 3 large eggs
- 1 ¾ cup plus 2 tbsp. all-purpose flourcake flour0.9:1baking
lighter crumb
- 1 ¼ tsp. baking soda
- ¾ tsp. salt
- 16 oz. fresh raspberries or frozen raspberries, thawed
- ⅓ cup sugar
- 3 tbsp. cornstarch
- 1 tsp. lemon juice
- 1 ¼ cup water
- 8 oz. bittersweet chocolate, finely chopped
- 1 cup heavy cream
- 3 tbsp. unsalted butter, at room temperature
- 1 cup sugar
- 4 large egg whites
- 2 ¼ tbsp. unsalted butter, at room temperature
- ⅓ cup raspberry puree, strained, from fresh or frozen raspberries
- ½ tsp. vanilla extract
- 4 oz. bittersweet chocolate, finely chopped
- ½ cup heavy whipping cream
- ¼ cup light corn syrup
- 2 tsp. vanilla extract
- fresh raspberries, for garnish
Instructions
- 1
Preheat oven to 350°F. Grease and flour the edges of three 9-inch round cake pans and line bottoms with parchment paper.
- 2
Combine cocoa and coffee powder in a small bowl. Add boiling water and whisk until smooth. Cool slightly and whisk in sour cream.
- 3
In an electric mixer bowl, beat butter and sugar on medium-high speed until light and fluffy, about 5 minutes.
- 4
Blend in eggs one at a time, scraping down bowl as needed. Beat in vanilla.
- 5
Combine flour, baking soda and salt in a small bowl. With mixer on low speed, add dry ingredients to mixing bowl in three additions, alternating with cocoa-sour cream mixture, beginning and ending with dry ingredients. Beat each addition just until incorporated.
- 6
Divide batter between prepared pans. Bake 35 minutes, or until a toothpick inserted in center comes out clean.
- 7
Cool in pans about 15 minutes, then transfer cakes to wire rack to cool completely.
- 8
For raspberry filling: In a medium saucepan, stir together water, sugar and cornstarch. Cook over medium-high heat, whisking occasionally, until mixture begins to bubble and thicken. Remove from heat and whisk in lemon juice. Fold in berries with a spatula. Cover and chill.
- 9
For ganache: Place chopped chocolate in a heatproof bowl. Heat cream in a small saucepan and bring to a simmer. Remove from heat and pour hot cream over chocolate. Let stand 1-2 minutes, then whisk until smooth. Whisk in butter one tablespoon at a time until incorporated. Let ganache sit to thicken, or place bowl in fridge or freezer, whisking every 10 minutes until desired consistency. Transfer about half cup of thickened ganache to a pastry bag fitted with a plain round tip about half inch in diameter.
- 10
Place one cooled cake layer on a cake board or serving platter. Spread half cup of ganache in an even layer over cake. Using reserved ganache in pastry bag, pipe a border around the perimeter of cake layer. Spoon raspberry filling inside ganache border in an even layer. Top with another cake layer and repeat with ganache and filling. Top with remaining cake layer.
- 11
For raspberry buttercream: Combine sugar and egg whites in a heatproof bowl set over a pot of simmering water. Heat, whisking frequently, until mixture reaches 160°F and sugar has dissolved. Transfer to stand mixer fitted with whisk attachment. Beat on medium-high speed until stiff peaks form and mixture has cooled to room temperature, about 8 minutes. Reduce speed to medium and add butter, 2 tablespoons at a time. If frosting looks soupy or curdled, continue to beat on medium-high speed until thick and smooth, about 3-5 minutes. Blend in raspberry puree and vanilla until smooth and completely incorporated. Frost top and sides of assembled cake, smoothing surface as much as possible. Chill for at least 30 minutes.
- 12
For chocolate glaze: Place chocolate in a medium bowl. Heat cream in a small saucepan over medium heat until simmering. Pour hot cream over chocolate and let sit 1-2 minutes. Whisk until completely smooth. Whisk in corn syrup and vanilla. Pour glaze into a pitcher or measuring cup and allow to cool for 10 minutes.
- 13
Slowly pour glaze over cake, ensuring top is covered and glaze drips over sides. Let glaze set about 5-10 minutes.
- 14
Garnish cake with fresh raspberries and chill until ready to serve.
Tips
Do not let chocolate glaze cool longer than 10 minutes or it may become difficult to pour over the cake.
When piping the ganache border, this well helps contain the raspberry filling and prevents it from running off the cake layers.
Use more raspberry filling than seems necessary; some will soak into and meld with the cake layers.
If frosting appears soupy or curdled during buttercream preparation, continue beating on medium-high speed for 3-5 minutes until it thickens and smooths again.
Good to Know
Refrigerate covered up to 3 days. Allow to come to room temperature about 20 minutes before serving.
Cake layers can be baked 1 day ahead and wrapped well. Raspberry filling, ganache, and buttercream can be made 1 day ahead. Assemble and glaze up to 8 hours ahead and refrigerate until serving.
Serve chilled or at room temperature. Slice with a sharp knife dipped in hot water and wiped clean between cuts.
Common Mistakes
Do not overbake the cake layers; a toothpick should come out clean but the cake should still be moist to avoid dryness.
Do not skip the 160°F temperature check for egg whites in the buttercream to avoid food safety issues.
Do not overmix the batter after adding dry ingredients to avoid a dense, tough crumb.
Do not let the chocolate glaze sit longer than 10 minutes before pouring or it will be too thick to coat smoothly.
Substitutions
Dairy-Free Swaps
General Alternatives
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