Ingredients
Scale
Chocolate Cake
- 2½ cups (300 g) all-purpose flour
- ¾ cup (65 g) unsweetened cocoa powder
- 2 cups (400 g) granulated sugar
- 2 teaspoons baking soda
- 1 teaspoon baking powder
- ½ teaspoon fine salt
- 3 large eggs, room temperature
- 1¼ cups (300 ml) buttermilk, room temperature
- ¾ cup (180 ml) neutral vegetable oil
- 2 teaspoons vanilla extract
- 1 cup (240 ml) hot freshly brewed coffee
Chocolate Buttercream
- 1½ cups (340 g) unsalted butter, softened
- ¾ cup (65 g) unsweetened cocoa powder
- 5 cups (600 g) powdered sugar
- ⅓–½ cup (80–120 ml) heavy cream, as needed
- 2 teaspoons vanilla extract
- ¼ teaspoon fine salt
Chocolate Ganache
- 10 oz (285 g) semisweet baking chocolate, finely chopped
- 1 cup (240 ml) heavy cream
Chocolate Candy Crunch Topping
- 6–8 chocolate-hazelnut truffles
- 4–6 chocolate-covered wafer sticks
- Additional chocolate wafer pieces
- 5–7 small chocolate sandwich cookies
- Milk chocolate drops
- White chocolate drops
- Chocolate curls or broken chocolate pieces
- 2 cups crushed dark chocolate cookies, divided
Instructions
- Prepare the pans. Preheat the oven to 350°F (175°C). Lightly grease three 8-inch square cake pans. Line their bottoms with parchment paper and lightly grease the parchment.
- Mix the dry ingredients. In a large bowl, whisk the flour, cocoa powder, granulated sugar, baking soda, baking powder, and salt for about 30 seconds.
- Mix the wet ingredients. In a separate bowl, whisk the eggs, buttermilk, vegetable oil, and vanilla until evenly combined.
- Make the batter. Pour the wet mixture into the dry ingredients. Mix gently until most dry streaks disappear. Slowly whisk in the hot coffee. The finished batter should be smooth and fairly thin.
- Divide the batter. Divide it evenly between the three prepared pans. For the most even layers, weigh the filled pans with a digital kitchen scale.
- Bake. Bake for 27–32 minutes. Start checking at 27 minutes. The centers should spring back lightly when touched, and a tester inserted in the middle should come out clean or with a few moist crumbs.
- Cool completely. Leave the cakes in their pans for 10–15 minutes. Turn them onto wire racks, remove the parchment, and cool completely before frosting.
- Prepare the buttercream. Beat the softened butter for about 3 minutes. Add the cocoa powder. Gradually add the powdered sugar, alternating with small amounts of heavy cream. Add vanilla and salt. Beat until fluffy but stable. Add additional cream 1 tablespoon at a time only if needed.
- Assemble the layers. Level pronounced domes if necessary. Place the first layer on a square cake board. Spread an even layer of buttercream over it. Repeat with the second layer. Place the third layer on top, preferably upside down for a flatter surface.
- Crumb coat. Spread a thin layer of buttercream over the top and all four sides. Refrigerate for 20–30 minutes, until firm.
- Apply the final frosting. Cover the chilled cake with the remaining chocolate buttercream. Smooth the sides while keeping the square corners visible. Slight spatula marks are fine.
- Prepare the ganache. Place finely chopped semisweet chocolate in a heatproof bowl. Heat the heavy cream until steaming with small bubbles appearing around the edge. Pour it over the chocolate. Leave untouched for 2–3 minutes, then stir gently from the center outward until smooth and glossy.
- Test the ganache. Allow it to cool until it has thickened. Test one drip on the cake. It should travel slowly down the side and stop before reaching the base. If it runs quickly, let the ganache cool longer.
- Cover the top. Spread ganache across the top and gently encourage several short and medium drips over the edges. Keep the drips irregular rather than perfectly spaced.
- Build the chocolate mound. While the ganache remains tacky, position the tallest wafer sticks toward the rear-center. Add truffles, sandwich-cookie pieces, broken wafers, milk and white chocolate drops, and chocolate pieces around them. Keep some glossy ganache visible.
- Create the cookie border. Use about 1½ cups of crushed dark cookies for the base. If the chilled buttercream is too dry for crumbs to stick, spread a very thin fresh layer of buttercream over the bottom 1–1½ inches. Press the crumbs around all four sides to form a thick dark border.
- Finish the cake. Scatter some of the remaining coarse cookie crumbs across the ganache and around the base. Chill only until the cake and decorations are stable.
- Serve. For better texture and flavor, remove the cake from the refrigerator about 30–60 minutes before serving. Cut into 16–20 portions.
Notes
- Do not add extra flour because the batter looks thin. The fluid consistency is intentional.
- All refrigerated cake ingredients should preferably be close to room temperature before mixing.
- Do not frost warm cake layers.
- Add heavy cream to the buttercream gradually. You may not need the full ½ cup.
- Finely chopped semisweet baking chocolate generally gives the ganache a smoother finish than shape-holding chocolate chips.
- Never pour very hot ganache directly onto chilled buttercream.
- Test one ganache drip before covering the entire cake.
- Put the tallest wafers toward the back so the cake keeps the same visual identity as the reference.
- Add exposed wafers as close to serving as practical for better crunch.
- Do not omit the thick cookie-crumb base. It is part of the signature appearance of this cake.
- Candy brands and sizes vary, so topping quantities can be adjusted slightly.
- Nutrition is an estimate and changes according to the exact candies, cookies, chocolate, buttermilk, cream, and serving size used.
- Prep Time: 1 hour 15 minutes
- Additional Time / Cooling & Decorating: 1 hour 30 minutes
- Cook Time: 30 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American-inspired