Marble Cake With Chocolate Ganache

Why You’ll Love This Recipe

• Classic vanilla and chocolate batters swirl into a striking marble pattern in every slice.
• Tender, moist crumb thanks to sour cream and a gentle mixing method.
• Glossy, pourable chocolate ganache adds a bakery-style finish with minimal effort.
• Easy to decorate: add a simple white chocolate swirl or pipe rosettes with thickened ganache.

Grocery List

• Produce: No fresh produce needed.
• Dairy: Unsalted butter, large eggs, sour cream, whole milk, heavy cream
• Pantry: All-purpose flour, granulated sugar, baking powder, fine salt, vanilla extract, unsweetened cocoa powder, instant espresso powder (optional), bittersweet chocolate, white chocolate (optional)

Full Ingredients

For the Marble Cake

• All-purpose flour: 210 g (1 3/4 cups), spooned and leveled
• Baking powder: 2 tsp
• Fine salt: 1/2 tsp
• Unsalted butter, softened: 170 g (3/4 cup)
• Granulated sugar: 200 g (1 cup)
• Large eggs, room temperature: 3
• Vanilla extract: 2 tsp
• Sour cream, room temperature: 120 g (1/2 cup)
• Whole milk, room temperature: 60 ml (1/4 cup)

For the Cocoa Paste (Chocolate Batter)

• Unsweetened cocoa powder: 25 g (1/4 cup)
• Instant espresso powder (optional, boosts chocolate flavor): 1 tsp
• Hot water (just off the boil): 60 ml (1/4 cup)

For the Chocolate Ganache

• Bittersweet chocolate (60–70%), finely chopped: 180 g
• Heavy cream: 180 g (3/4 cup)
• Unsalted butter (optional, for extra gloss): 14 g (1 tbsp)

Optional Decoration

• White chocolate, melted for marbled swirl: 28 g (1 oz)
• Chocolate curls or sprinkles for finishing: 1–2 tbsp

Step-by-Step Instructions

Step 1: Prep the pan and oven

Heat the oven to 350°F (175°C) with a rack in the center. Lightly grease an 8-inch (20 cm) round cake pan with butter or nonstick spray, line the base with a parchment circle, and grease the parchment. This ensures a clean release and neat edges.

Step 2: Bloom the cocoa for deeper chocolate flavor

In a small bowl, whisk together the cocoa powder and instant espresso powder. Pour in the hot water and whisk until smooth and glossy. Set aside to cool to lukewarm. Blooming the cocoa intensifies flavor and gives the chocolate batter a silky texture.

Step 3: Cream butter and sugar; add eggs and vanilla

In a large bowl with a hand mixer or stand mixer fitted with the paddle, beat the softened butter and sugar on medium speed until pale and fluffy, 3 minutes. Scrape the bowl. Add the eggs one at a time, beating well after each. Mix in the vanilla. The mixture should look creamy and emulsified.

Step 4: Finish the vanilla batter

Whisk the flour, baking powder, and salt in a separate bowl. In a measuring jug, whisk the sour cream and milk until smooth. Add the dry ingredients to the butter mixture in 3 additions, alternating with the sour cream-milk in 2 additions (dry, wet, dry, wet, dry). Mix on low just until combined and no dry spots remain. Do not overmix.

Step 5: Make the chocolate batter and marble

Scoop about one-third of the batter—approximately 420 g (about 2 cups)—into a medium bowl. Whisk in the cooled cocoa paste until evenly combined. To marble: add alternating dollops of vanilla and chocolate batters into the prepared pan. Use a thin knife or skewer to swirl with 2–3 figure-eight motions. Avoid over-swirl; you want distinct ribbons.

Step 6: Bake and cool

Bake on the center rack for exactly 50 minutes, until the top springs back lightly and a toothpick inserted in the center comes out with a few moist crumbs. Cool in the pan for 15 minutes, then run a thin knife around the edge, invert onto a rack, peel away parchment, and turn right-side up. Cool completely, about 75 minutes, before glazing.

Step 7: Make the ganache, glaze, and decorate

Place the chopped chocolate in a heatproof bowl. Heat the cream in a small saucepan until steaming and just starting to bubble at the edges; do not boil. Pour over the chocolate, cover, and let stand 2 minutes. Stir slowly from the center until smooth and glossy; add the butter (if using) and stir to melt. Cool 10–15 minutes until pourable but not runny.

Set the fully cooled cake on a rack over a tray. Pour ganache over the center and coax to the edges so it drips naturally. If desired, drizzle thin lines of melted white chocolate across the ganache and drag a skewer through the lines to create a marbled effect. Let set for 10 minutes. For rosettes, reserve a little ganache, let it thicken to piping consistency, then pipe along the border.

Pro Tips

• Use room-temperature butter, eggs, and dairy so the batter emulsifies and rises evenly.
• Weigh ingredients for accuracy, especially flour and chocolate; small variations affect crumb and ganache texture.
• Blooming cocoa with hot water creates a smoother, more intense chocolate batter—do not skip.
• Swirl gently and sparingly; too much swirling blends batters and loses the marble effect.
• Slice with a warm, dry serrated knife for the cleanest, show-stopping slices.

Variations

• Bundt Marble Cake: Bake in a greased 10-cup Bundt pan at 350°F (175°C) for 55 minutes. Double ganache for dramatic coverage.
• Mocha Marble: Replace the milk with strong brewed coffee (60 ml) and use the espresso powder in the cocoa paste for a latte-like aroma.
• Orange-Chocolate Marble: Add 1 tbsp finely grated orange zest to the vanilla batter and 1/2 tsp orange extract to the ganache.

Storage & Make-Ahead

Store the glazed cake under a cake dome at cool room temperature for up to 3 days. Refrigerate up to 5 days; bring to room temperature before serving for best ganache texture. To freeze, wrap the unglazed cake tightly and freeze up to 2 months; thaw overnight in the fridge, then glaze. To freeze glazed slices, chill until the ganache is firm, wrap well, and freeze up to 1 month; thaw wrapped in the fridge. Leftover ganache keeps refrigerated 1 week; rewarm gently until spreadable.

Nutrition (per serving)

Approximate values for 1 of 12 servings (without optional white chocolate garnish): 455 calories; 25 g fat; 40 g carbohydrates; 6 g protein; 2 g fiber; 280 mg sodium; 28 g sugars.