Ingredients
For the Chocolate Cake
- 2½ cups (300 g) all-purpose flour
- 2 cups (400 g) granulated sugar
- ¾ cup (65–75 g) unsweetened cocoa powder
- 2 teaspoons baking powder
- 2 teaspoons baking soda
- ½ teaspoon fine salt
- 3 large eggs, room temperature
- 1¼ cups (300 ml) whole milk, room temperature
- ½ cup (120 ml) neutral vegetable oil
- 2 teaspoons vanilla extract
- 1 cup (240 ml) hot brewed coffee
For the Vanilla Buttercream
- 1½ cups (340 g) unsalted butter, softened
- 5 cups (600 g) powdered sugar
- ⅓ cup (80 ml) heavy cream
- 2 teaspoons vanilla extract
- ¼ teaspoon fine salt
For the Chocolate-Hazelnut Filling
- 8 oz (225 g) full-fat cream cheese, softened
- ½ cup (150 g) chocolate-hazelnut spread
- 1 cup (240 ml) cold heavy whipping cream
- ½ cup (60 g) powdered sugar
For the Chocolate Ganache
- 8 oz (225 g) semisweet chocolate, finely chopped
- ⅔ cup (160 ml) heavy cream
For Decorating
- 6–8 chocolate-covered wafer fingers
- 6–8 chocolate-hazelnut truffles
- 8–12 milk chocolate balls
- 1–2 segmented chocolate bars, broken into pieces
- ½ cup chocolate-covered crispy pieces
- Chocolate curls or shavings, as needed
Important: decoration amounts are intentionally approximate. Candy brands, bar sizes, and the desired arrangement can vary. This is also why nutrition for a decorated cake can only be an estimate unless the exact brands and weights are entered into a nutrition calculator.
Instructions
- Prepare the pans. Preheat the oven to 350°F (175°C). Grease four 8-inch square cake pans. Line the bottoms with parchment paper and lightly grease the parchment.
- Mix the dry ingredients. In a large bowl, whisk the flour, sugar, cocoa powder, baking powder, baking soda, and salt until evenly combined and free of cocoa lumps.
- Add the wet ingredients. Add the eggs, whole milk, vegetable oil, and vanilla. Mix on low speed until just combined.
- Add the coffee. Slowly pour in the hot coffee while mixing on low speed. The batter will be relatively thin. This is normal.
- Divide the batter. Divide the batter evenly among the four prepared pans. For the most even layers, weigh the batter and place the same amount in each pan.
- Bake. Bake for approximately 20–25 minutes. Begin checking around 18–20 minutes because oven and pan performance varies. The center should spring back lightly when touched, and a toothpick should come out with a few moist crumbs but no wet batter.
- Cool completely. Let the cakes cool in their pans for about 10 minutes. Turn them onto wire racks, remove the parchment, and allow them to cool completely before filling or frosting.
- Make the chocolate filling. Beat the softened cream cheese until smooth. Add the chocolate-hazelnut spread and mix until uniform. In a separate chilled bowl, whip the cold heavy cream with the powdered sugar to medium-stiff peaks. Fold the whipped cream gently into the chocolate mixture. Refrigerate until needed.
- Make the buttercream. Beat the softened butter for 3–4 minutes until pale and creamy. Gradually add the powdered sugar. Add the heavy cream, vanilla, and salt. Beat for another 3–5 minutes until light but firm enough to hold square edges.
- Build the first layer. Place one completely cooled chocolate cake layer on a sturdy square cake board. Pipe a buttercream dam around the perimeter and fill the center with vanilla buttercream.
- Add the chocolate center. Place the second cake layer on top. Pipe a buttercream dam around its edge, then fill the center with the chocolate-hazelnut cream.
- Finish the layers. Add the third cake layer. Spread or pipe another layer of vanilla buttercream. Top with the fourth chocolate cake layer.
- Crumb-coat the cake. Apply a thin layer of vanilla buttercream over the top and all four sides. Refrigerate for 20–30 minutes, or until the crumb coat feels firm.
- Apply the final frosting. Cover the chilled cake with the remaining vanilla buttercream. Smooth each side with a straight scraper. Work the frosting into the corners to create clean square edges. Chill for at least 30 minutes.
- Make the ganache. Place the finely chopped chocolate in a heatproof bowl. Heat the cream until steaming and just beginning to simmer around the perimeter. Pour it over the chocolate and leave untouched for 2–3 minutes. Stir gently from the center outward until smooth and glossy.
- Test the drip. Let the ganache cool until fluid but no longer hot. Place one test drip on the back of the cold cake. If it runs straight to the bottom, wait a little longer. If it barely moves, gently warm the ganache.
- Decorate the cake. Once the test drip has the right consistency, create individual drips around the edges and spread a thin layer of ganache across the top.
- Create the candy explosion. Position the tall wafer fingers first, angling them slightly. Add truffles and larger chocolate-bar pieces around them. Fill the gaps with chocolate balls, crispy pieces, broken wafers, and chocolate curls.
- Chill before serving. Refrigerate until the cake and filling are stable. For a softer eating texture, remove the cake from the refrigerator for a short period before serving, while observing safe handling for its dairy-based filling.
Notes
For the closest match to the reference cake, use four thinner square chocolate layers rather than three thick layers. The filling order should be vanilla, chocolate-hazelnut, then vanilla.
The cake layers must be completely cool before assembly. Warm cake will soften the filling and buttercream.
For sharp square edges, chill the crumb-coated cake for 20–30 minutes before applying the final buttercream.
Always apply ganache to a cold, firm buttercream surface. Test one drip before decorating the entire cake.
If the ganache runs too quickly, allow it to cool further. If it is too thick, warm it very gently.
Because the filling contains cream cheese and whipped cream, refrigerate the finished cake at 40°F (4.4°C) or below. Do not leave perishable food at room temperature for more than two hours.
Candy quantities are flexible. For the reference appearance, combine tall wafer bars with round truffles, chocolate balls, segmented bars, and smaller crispy pieces.
- Prep Time: 1 hour 15 minutes
- Additional Time / Chilling & Cooling Time:: 2 hours 30 minutes
- Cook Time: 22 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American-inspired