Say hello to the BEST marble cake around! Light, tender, and layered with an airy chocolate buttercream, this classic marble cake balances butter’s flavor with oil’s moisture for a cake both vanilla and chocolate lovers will adore.
What is marble cake?
Marble cake is made by combining two batters—traditionally vanilla and chocolate—and gently swirling them together to create a marbled pattern. Typically you prepare a single base batter, set aside a portion, and add cocoa to that portion to form the chocolate batter. The technique is versatile and works with many flavor combinations, but this recipe focuses on the timeless vanilla-and-chocolate version.
How to make marble cake
- Dry ingredients: Whisk together all-purpose flour, cornstarch, baking powder, baking soda, and salt. Cornstarch helps mimic cake flour by reducing gluten development, which keeps the crumb soft and spongy.
- Buttermilk substitute: If you don’t have buttermilk, mix whole milk with a little white vinegar and let it sit for a few minutes until it thickens slightly. The acidity tenderizes the crumb and improves rise.
- Butter and oil: Cream butter, oil, and sugar until smooth. Butter brings flavor and structure; oil adds moisture. The mixture may look a bit grainy but should be lump-free.
- Finish the vanilla batter: Beat in the eggs one at a time, then add vanilla. Alternate folding in the dry ingredients and the buttermilk, beginning and ending with the dry mix. Adding them gradually prevents overmixing and keeps the cake tender.
- Make the chocolate batter: In a separate bowl mix cocoa (and optional black cocoa) with a few tablespoons of milk until smooth. Stir about half of the vanilla batter into the cocoa mixture to form the chocolate portion.
How to marble the cake
My preferred method creates a bold marbled look. Use a spoon or cookie scoop to drop alternating dollops of vanilla and chocolate batter into the pan, forming a loose checkerboard pattern. Avoid placing like batters right next to each other when possible.
Then, run a knife or skewer lengthwise and widthwise through the batter to swirl. Don’t over-swirl—light, deliberate passes will preserve the contrast and yield a beautiful marble pattern. Bake as directed once swirled.
How to make chocolate frosting
Once the cakes are baked and cooled, make the chocolate buttercream. It’s simple and pairs perfectly with the marble layers. The process in short:
- Butter and sugar: Beat butter and sifted powdered sugar together on low until the sugar is mostly dissolved and the mix is cohesive.
- Add remaining ingredients: Add sifted cocoa, a pinch of salt, vanilla, and a few tablespoons of milk. Mix on low to combine.
- Whip: Increase speed and whip until light and fluffy. Add milk, a tablespoon at a time, if you need to thin the frosting.
- Decorate: Layer the cooled cakes with frosting, then finish the outside as you like before slicing and serving.
FAQs
Can I omit the cornstarch?
Cornstarch lightens the flour and helps create a softer crumb. You can skip it, but the cake will be slightly less tender. To replace 2 tablespoons cornstarch, add about 1/4 cup (33g) extra all-purpose flour.
Why use black cocoa powder?
Black cocoa deepens the chocolate color and intensifies flavor in the chocolate portion. It’s optional—omit it if you don’t have any.
Can I bake this in 9-inch pans or a sheet pan?
Yes. Use two 9″ pans (check a few minutes earlier for doneness), three 6″ layers (about 35–40 minutes), or a 9×13″ sheet cake (about 30–35 minutes). Adjust baking time and test with a skewer for moist crumbs.
Tips for a moist marble cake
- Measure flour accurately: Use a scale for best results. If using cups, spoon the flour into the cup and level it—do not scoop directly from the bag.
- Room temperature ingredients: Let eggs, butter, and milk come to room temperature for even mixing and smooth batter.
- Avoid overmixing: Overmixing develops gluten and leads to a dense cake. Mix only until ingredients are combined.
- Proper cooling: Let cakes cool in the pan for about 10 minutes after baking, then turn them onto a wire rack to finish cooling. This helps them hold their shape while staying moist.
- Frosting texture: Sift powdered sugar and cocoa for a silky buttercream. Add milk a tablespoon at a time to reach your preferred consistency.
- Decorating: Make sure cakes are completely cool before frosting, or the buttercream may soften and slide.
Ingredients
For the vanilla cake base:
- 2 ½ cups (325g) all-purpose flour, spooned and leveled
- 2 tbsp cornstarch
- 2 tsp baking powder
- ½ tsp baking soda
- ½ tsp salt
- 1 ½ cups (360mL) milk, room temperature
- 1 ½ tbsp white vinegar
- ½ cup (115g) unsalted butter, room temperature
- ⅓ cup (80mL) vegetable oil or other neutral oil
- 1 ½ cups (300g) granulated sugar
- 3 large eggs, room temperature
- 2 tsp pure vanilla extract
For the chocolate marble:
- ¼ cup (20g) unsweetened cocoa powder
- 1 tsp black cocoa powder (optional)
- 5 tbsp whole milk, room temperature
For the chocolate buttercream frosting:
- 1 ½ cups (340g) unsalted butter, room temperature
- 4 cups (520g) powdered sugar, sifted
- 1 cup (80g) unsweetened cocoa powder, sifted
- Pinch of salt
- 3–4 tbsp milk
- 1 tsp pure vanilla extract
Instructions
Marble Cake:
- Preheat oven to 350°F (175°C). Butter two 8″ or 9″ round pans, line bottoms with parchment, and flour the sides, tapping out excess.
- Whisk flour, cornstarch, baking powder, baking soda, and salt in a medium bowl; set aside.
- Combine milk and vinegar in a measuring cup and let sit about 5 minutes to thicken slightly.
- Cream butter, oil, and sugar until smooth and lump-free.
- Add eggs one at a time, mixing after each. Stir in vanilla with the last egg.
- Alternate adding dry ingredients and milk to the butter mixture, beginning and ending with dry ingredients: ⅓ dry, half milk, ⅓ dry, remaining milk, finish with last ⅓ dry.
- Whisk cocoa (and optional black cocoa) with 5 tbsp milk until smooth. Stir about half the vanilla batter into the cocoa mixture until even.
- Using a scoop or spoon, drop alternating dollops of vanilla and chocolate batter into the pans to form a loose checkerboard pattern.
- Swirl gently with a skewer or knife lengthwise and widthwise; avoid over-swishing to preserve the marble contrast.
- Bake for 30–35 minutes for 8″ pans (25–30 minutes for 9″ pans) or until a skewer comes out clean with a few moist crumbs.
- Cool in pans for 10 minutes, then invert onto a wire rack and cool completely to room temperature before frosting.
Chocolate Buttercream:
- Beat butter and sifted powdered sugar together on low until the sugar is mostly incorporated.
- Add sifted cocoa, salt, 3 tbsp milk, and vanilla; mix on low until combined.
- Increase speed and whip until smooth and fluffy. If too thick, add more milk 1 tbsp at a time.
- Place one cooled layer on a cake stand, spread frosting, top with second layer, and finish frosting the outside.
Enjoy!
If you prefer an older version of this recipe, a simple sheet cake adaptation and alternate ingredient amounts are provided below for convenience.
Sheet cake version — Ingredients
- 2 cups (260g) all-purpose flour
- 2 tbsp cornstarch
- 2 tsp baking powder
- ½ tsp baking soda
- ¼ tsp salt
- ½ cup (115g) unsalted butter, softened
- 1 cup (200g) granulated sugar
- 2 large eggs, room temperature
- 1 tsp pure vanilla extract
- 1 ¾ cups (420mL) milk total, divided (1 ½ cups + ¼ cup)
- ¼ cup (20g) unsweetened cocoa powder
Sheet cake version — Instructions
- Grease a 9×13″ pan and preheat oven to 350°F (175°C).
- Sift together flour, cornstarch, baking powder, baking soda, and salt; set aside.
- Cream butter and sugar until pale and fluffy. Add eggs one at a time, then vanilla.
- Alternate adding dry ingredients and 1 ½ cups milk, starting and ending with the dry mix, mixing until just combined.
- Reserve about 1 cup of batter for the chocolate marble; pour the remaining vanilla batter into the prepared pan.
- Whisk cocoa with the remaining ¼ cup milk to form a smooth paste, then combine with the reserved batter.
- Spoon the chocolate batter over the vanilla layer and swirl with a knife or skewer to create a marble effect.
- Bake for 25–30 minutes or until a skewer inserted into the center comes out clean. Cool completely in the pan before frosting or slicing.
- Enjoy!