Rich Chocolate Layer Cake With Vanilla Buttercream

Why You’ll Love This Recipe

• Intense, layered chocolate flavor from both cocoa powder and real melted chocolate, bloomed with hot coffee.
• Ultra-moist crumb thanks to sour cream and oil—tender slices that keep beautifully.
• Silky vanilla buttercream that’s luscious yet balanced, perfect with deep chocolate.
• Elegant finish with easy chocolate shavings or curls—special-occasion looks with weeknight simplicity.

Grocery List

• Produce: None
• Dairy: Unsalted butter, eggs, sour cream, whole milk, heavy cream
• Pantry: All-purpose flour, Dutch-process cocoa powder, granulated sugar, light brown sugar, baking powder, baking soda, fine sea salt, neutral oil, vanilla extract or paste, strong coffee, semisweet chocolate (bar), confectioners’ sugar, chocolate bar for curls

Full Ingredients

Chocolate Cake Layers

• All-purpose flour: 2 3/4 cups (345 g)
• Dutch-process cocoa powder: 1 cup (90 g) — natural cocoa works but yields a lighter color
• Granulated sugar: 2 1/2 cups (500 g)
• Light brown sugar: 1/2 cup, packed (100 g)
• Baking soda: 2 tsp
• Baking powder: 1 1/2 tsp
• Fine sea salt: 1 tsp
• Neutral oil (canola, grapeseed, or vegetable): 3/4 cup (180 ml)
• Sour cream: 1 cup (240 g), at room temperature
• Whole milk: 3/4 cup (180 ml), at room temperature
• Large eggs: 4, at room temperature
• Pure vanilla extract: 2 tsp (10 ml)
• Strong hot brewed coffee: 1 cup (240 ml)
• Semisweet or bittersweet chocolate (60–70%), finely chopped and melted: 6 oz (170 g)

Vanilla Buttercream

• Unsalted butter: 2 cups (454 g), softened to cool room temperature
• Confectioners’ sugar: 7 cups (840 g), sifted
• Heavy cream: 1/2 cup (120 ml), plus 1–3 tbsp as needed for consistency
• Vanilla bean paste or pure vanilla extract: 2 1/2 tsp (12 ml)
• Fine sea salt: 1/4 tsp

To Finish

• Chocolate shavings or curls: 2–3 oz (60–85 g) made from a chocolate bar

Step-by-Step Instructions

Step 1: Prep the pans and preheat

Preheat the oven to 350°F (177°C) with a rack in the center. Grease three 8-inch round cake pans with butter or nonstick spray, line each with a parchment circle, then lightly dust with cocoa powder (it blends into dark cake better than flour). Tap out the excess.

Step 2: Melt chocolate and bloom the cocoa

Place the chopped chocolate in a heatproof bowl and melt gently (microwave at 50% power in 30-second bursts, stirring, or set over barely simmering water). In a separate bowl or large measuring cup, whisk the cocoa with the hot coffee until smooth and glossy; let stand 2–3 minutes to bloom. Whisk the melted chocolate and 2 tsp vanilla into the coffee-cocoa mixture. Cool until warm, not hot (about 95–110°F). If it thickens, it’s fine—just keep it pourable.

Step 3: Combine the dry ingredients

In a large mixing bowl (or the bowl of a stand mixer), whisk together flour, granulated sugar, brown sugar, baking soda, baking powder, and salt for 30 seconds to evenly distribute the leaveners and break up any lumps of sugar.

Step 4: Whisk the wet ingredients

In a separate bowl, whisk the eggs, oil, sour cream, and milk until completely smooth. Gradually whisk in the warm chocolate-coffee mixture until uniform. If the mixture is still quite warm, stream it in slowly while whisking to avoid curdling the eggs.

Step 5: Make the batter and divide

Pour the wet mixture into the dry ingredients. Mix on low speed (or whisk by hand) just until the batter is smooth and no dry streaks remain, scraping the bowl and bottom once. The batter will be glossy and pourable. Divide evenly among the prepared pans (about 2 1/2 cups per pan, or weigh for precision). Smooth the tops and tap each pan firmly on the counter to release large air bubbles.

Step 6: Bake and cool

Bake 24–28 minutes, rotating pans halfway, until the centers spring back lightly and a toothpick comes out with a few moist crumbs. Cool on a rack for 10 minutes, then turn out, remove parchment, and cool completely (about 1 hour). If necessary, level domed tops with a long serrated knife before assembling.

Step 7: Make the vanilla buttercream

Beat the softened butter on medium-high speed until very pale and fluffy, 3–4 minutes. Reduce speed to low and gradually add half the confectioners’ sugar. Add the heavy cream (start with 1/2 cup), vanilla, and salt; mix until combined. Add remaining sugar slowly, then increase speed to medium-high and whip until light and silky, 2–3 minutes. Adjust with a tablespoon or two more cream for a smooth, spreadable consistency. For an ultra-smooth finish, switch to the paddle attachment and beat on low 30–60 seconds to knock out excess air.

Step 8: Assemble, frost, and garnish

Place one cake layer on a stand and secure with a small dab of frosting. Spread 1 to 1 1/4 cups buttercream evenly to the edges. Add the second layer and repeat. Top with the third layer, placing it upside down for the flattest surface. Apply a thin crumb coat over the entire cake and chill 15–20 minutes to set. Finish with a generous final coat, smoothing the sides with a bench scraper or keeping soft swirls with an offset spatula. Garnish with chocolate shavings or curls on top and around the base. Slice with a hot, dry knife for clean layers.

Pro Tips

• Blooming cocoa in hot coffee deepens flavor and color—let it cool to warm before combining with eggs.
• Weigh ingredients and divide batter by weight for perfectly even layers.
• Use cocoa to dust pans so there’s no pale ring on your dark layers.
• For level layers, bake with cake strips or insulate pans with damp paper towels wrapped in foil.
• If buttercream gets too airy or bubbly, finish with 30–60 seconds on low speed with the paddle.

Variations

• Mocha Buttercream: Replace 2 tbsp of the cream with 2 tbsp hot espresso; dissolve 2 tsp instant espresso in the cream before adding.
• Raspberry Layer: Spread a thin layer (about 1/3 cup per layer) of seedless raspberry jam over each cake layer before the buttercream filling.
• Ganache Drip: Stir 6 oz (170 g) hot cream into 6 oz (170 g) finely chopped semisweet chocolate; cool until thick but pourable, then drip over the chilled frosted cake.

Storage & Make-Ahead

Baked, cooled cake layers can be wrapped well and kept at room temperature up to 1 day or frozen up to 2 months (thaw wrapped at room temperature). Buttercream keeps refrigerated up to 5 days or frozen up to 2 months; bring to room temperature and re-whip. Assembled cake holds 2 days at cool room temperature (covered) or up to 5 days refrigerated; bring to room temperature 45–60 minutes before serving for the best texture.

Nutrition (per serving)

Approximate for 1/16 of the cake: 670 calories; 34 g fat (20 g saturated); 84 g carbohydrates; 3–4 g fiber; 62 g sugars; 6–7 g protein; 360 mg sodium. Values are estimates and will vary with specific ingredients.