Marble Cake

This two-layer marble cake is made by swirling together chocolate and vanilla cake batter. The whole thing is then topped with a rich and creamy chocolate frosting!

📝 Ingredients

• 3 cups (345 grams) cake flour ((spooned & leveled))
• 2 teaspoons baking powder
• 1/2 teaspoon baking soda
• 1/2 teaspoon salt
• 1 cup (240 ml) buttermilk ((room temperature))
• 1/4 cup (60 ml) canola or vegetable oil
• 1 tablespoon (15 ml) pure vanilla extract
• 1/3 cup (30 grams) unsweetened cocoa powder
• 1/4 cup (60 ml) hot water
• 1 cup (2 sticks, or 230 grams) unsalted butter ((softened))
• 2 cups (400 grams) granulated sugar
• 4 large eggs ((room temperature))
• 1 1/4 cups (2.5 sticks, or 285 grams) unsalted butter ((softened))
• 4 cups (480 grams) powdered sugar
• 2/3 cup (60 grams) unsweetened cocoa powder
• 4 to 6 tablespoons (60 to 80 ml) whole milk
• 1 1/2 teaspoons pure vanilla extract
• 1/8 teaspoon salt

👨‍🍳 Instructions

1. 1--- To make the marble cake: ---
2. 2Preheat the oven to 350°F (180°C). Spray two 9-inch round cake pans with nonstick cooking spray, line the bottom of the pans with parchment paper, and set aside.
3. 3In a large mixing bowl, whisk the cake flour, baking powder, baking soda, and salt together until well combined. Set aside.
4. 4In a large bowl or measuring cup, whisk the buttermilk, oil, and vanilla extract together until well combined. Set aside.
5. 5In a separate mixing bowl, whisk the cocoa powder and water together until well combined and no lumps remain. Set aside to cool.
6. 6In the bowl of a stand mixer fitted with the paddle attachment or in a large mixing bowl using a handheld mixer, beat the butter on low speed until smooth, then slowly mix in the granulated sugar.
7. 7Once all of the sugar is added, increase to medium speed and continue mixing for another 4 to 5 minutes or until the mixture is light and fluffy.
8. 8Mix in the eggs, one at a time, making sure to stop and scrape around the bottom and sides of the bowl after each egg.
9. 9Add the dry ingredients in three additions alternating with the buttermilk mixture (begin and end with the dry ingredients) on low speed. Mix in each addition until just combined, making sure not to over mix the batter.
10. 10Use a rubber spatula to scrape around the bottom and sides of the bowl to ensure that everything is well combined.
11. 11Remove 2 cups (430 grams) of vanilla cake batter and transfer to a clean mixing bowl. Add the cocoa powder mixture and gently mix until well combined.
12. 12Pour some of the vanilla cake batter into each pan and spread around into one even layer. Alternate spoonfuls of the chocolate cake batter and remaining vanilla cake batter, making sure to evenly distribute both between the two pans.
13. 13Use a knife to gently swirl the batter to create a marble effect. Gently shake or tap the pans on the counter to level out the batter.
14. 14Bake for 28 to 33 minutes or until a toothpick inserted into the center of the cakes comes out clean. Remove from the oven and allow to cool in the pans for about 20 minutes. Slide a knife around the outside of the cakes, then carefully remove the cakes from the pans, and transfer to a wire rack to cool completely.
15. 15--- To make the chocolate frosting: ---
16. 16In the bowl of a stand mixer fitted with the paddle attachment or in a large mixing bowl using a handheld mixer, beat the butter on medium speed until smooth.
17. 17Mix in the powdered sugar on low speed, one cup at a time, making sure to mix well after each addition.
18. 18Add the cocoa powder, 4 tablespoons of milk, vanilla extract, and salt and mix on low-medium speed until fully combined, making sure to stop and scrape down the sides of the bowl. If needed, add another 1 to 2 tablespoons of milk.
19. 19--- To assemble the cake: ---
20. 20Level the tops of each cake with a knife or cake leveler. Place one of the cakes on a cake stand, top with a layer of frosting, and smooth it out into one even layer. Place the second layer on top, then use the remaining frosting to frost the top and sides of the cake.