Marble Cake

Say hello to the BEST marble cake around!! It's light and fluffy and layered with an airy chocolate buttercream frosting. Made with a mixture of butter and oil to give it the perfect balance of flavor and moisture, it's the perfect cake for both chocolate and vanilla lovers!

what is marble cake?

Marble cake is made up of 2 cake batters (traditionally vanilla and chocolate cake batter) that are swirled together to create a marbling effect (hence the name!) These two flavors are usually made with the same base batter, with some of it set aside and combined with cocoa powder to make the chocolate batter. There are a million different cake flavors that can be made using this same idea, but today, we're making the classic version!

how to make marble cake

1. Dry ingredients: Start by whisking together flour, cornstarch, baking powder & soda, and salt to combine. Cornstarch is one of the secrets to an extra spongy cake because it lightens it up, reduces the amount of gluten, and basically acts like a makeshift cake flour!
2. Buttermilk: I can NEVER find buttermilk in any store, so I always make my own at home. To make this substitute, simply mix together whole milk and vinegar and let them sit together until it starts to thicken and curdle slightly. The added acidity from the vinegar makes the cake extra tender and airy.
3. Butter and oil: While the buttermilk sits, it's time to cream together butter, oil, and sugar. Butter adds delicious flavor and a bit of structure to the cake while oil helps keep the cake soft and moist. Cream everything together until lump free - it will look a little grainy but that's fine.

4. Finishing the vanilla batter: To finish up the main cake batter, whisk the eggs and vanilla into the butter mixture and then alternate mixing in the dry ingredients and buttermilk. It's important to mix in the dry ingredients and buttermilk gradually to ensure the ingredients incorporate evenly and with less risk of overmixing. If you were to dump everything together, the batter may separate and it will be more likely that the gluten is overworked (which will make the cake dense and tough).
5. Chocolate swirl: In a separate bowl, whisk together cocoa powders and milk until smooth. Add in about half of the vanilla batter and mix together to create the chocolate portion of the cake.

how to marble cake

There are a lot of different ways to marble a cake, but this is my personal favorite technique - and I feel it gives it the best marbly look!

To start, use a spoon or cookie scoop to drop alternating blobs of vanilla and chocolate batter into the bottom of the pans. It should almost look like a bubbly chess board. Try to avoid putting 2 drops of the same batter next to each other, but if you need to, it's not a huge deal.

Using a knife or a skewer, swirl the batter by running the utensil up and down the baking pan lengthwise and then again side to side widthwise. Take care not to over swirl the batter or you'll loose that beautiful marble look. Now, the cakes are ready to go into the oven.

how to make chocolate frosting

Once the cakes have baked and cooled, it's time to make the rich and decadent chocolate buttercream frosting! It's super easy to whip up and pairs perfectly with this marble cake. Making this frosting can be summed up in 3 simple steps:

1. Butter and sugar: The buttercream starts by mixing together butter and sugar until the sugar has dissolved and the mixture is smooth. It's best to use an electric mixer for the frosting because otherwise it's a REAL workout! Mix the sugar into the butter on low speed to ensure the sugar doesn't go all over the place.
2. Remaining ingredients: Once the butter mixture is smoothened out, drop all the remaining frosting ingredients into the bowl. Mix again on low speed until everything is well combined.
3. Whip: Crank the mixer speed up to high and whip the frosting until it's smooth and fluffy. If you find it's too thick, add a splash more milk to thin it out to your desired consistency.
4. Decorate: And the final step before you can actually dig in! Layer the cooled cakes and frosting then decorate the outside however you'd like before slicing and serving.

FAQs

Can I leave out the cornstarch in the cake?
Cornstarch is used to make a quick and easy cake flour substitute. Cornstarch absorbs more liquid per tablespoon when compared to flour, which means we need less to achieve the same batter consistency. This ultimately helps lighten up the entire cake texture. You can leave it out, but the cake will be less soft. Substitute the 2 tablespoons of cornstarch with ¼ cup (33g) more all-purpose flour if you want to make the switch.

Why black cocoa powder?
I like adding a bit of black cocoa powder to the chocolate portion of the cake to naturally darken it and give it a richer flavor. If you don't want to use it, that's totally fine! You can just leave it out entirely.

Can I make this cake in 2 (9 inch) pans instead?
Yes! I would just start checking on the cakes about 5 minutes earlier. You can also use this recipe to make (3) 6" cake layers - the bake time will be around 35-40 minutes - or a 9x13" sheet cake - the bake time will be around 30-35 minutes.

tips for making MOIST marble cake

1. Flour: It's always best to measure flour using a food scale to ensure you have the exact amount. But if you are measuring with cups, make sure to use the "spoon and level" method: use a spoon to lightly scoop flour into your measuring cup then use a flat utensil to level off any excess. Don't scoop the measuring cup directly into the bag of flour or this can pack in excess weight worth of flour and dry out the cake.
2. Room temperature: Before starting the cake or frosting, allow all the ingredients to come up to room temperature. Cold ingredients will be more difficult to mix together and will create an uneven texture.
3. Mixing: Watch out for overmixing when whipping up the cake batter! It can cause the centers to sink and can overwork the gluten in the flour (which will lead to a dense cake).
4. Baking & cooling: Cakes can continue to overbake and dry out as they sit in their pans so they shouldn't be cooled completely in the pan. BUT they will also be too delicate to flip out of the pans when they're fresh from the oven. The perfect amount of time to wait before flipping these cakes onto a wire rack is around 10 minutes after they come out of the oven. This is enough time for the fats and sugars to solidify slightly and give the cake enough structure to transfer while also keeping the cakes perfectly moist.
5. Frosting: I HIGHLY recommend sifting the powdered sugar and cocoa powder for this frosting to ensure you get a smooth mixture without any uneven bumps or clumps. This frosting recipe makes enough to cover the outside of the cake in a thick fluffy layer or enough to cover the cake in a thinner layer with some leftover frosting for piping designs.
6. Decorating: Make sure to cool the cakes COMPLETELY to room temperature before layering / decorating or the buttercream will melt.

check out these other recipes!

• Chocolate Cake
• BEST Vanilla Cupcakes
• Perfect Brownies
• Black Forest Cake

Lastly, if you made this or any of my recipes, be sure to leave a comment and review below! I love hearing your thoughts! Also tag me on Instagram @eatsdelightfulblog so I can see what you're making.

Print

Enjoy!

* This post has been recently updated with a new recipe. If you love the old version, you can find it below!

Ingredients:

• 2 cups (260g) all-purpose flour
• 2 tablespoons cornstarch
• 2 teaspoons baking powder
• ½ teaspoon baking soda
• ¼ teaspoon salt
• ½ cup (1 stick / 115g) unsalted butter, softened to room temperature
• 1 cup (200g) granulated sugar
• 2 large eggs, at room temperature
• 1 teaspoon pure vanilla extract
• 1 & ½ cups (360mL) + ¼ cup (60mL) milk, divided
• ¼ cup (20g) unsweetened cocoa powder

Instructions:

1. Grease a 9×13 inch baking dish with butter and/or line with parchment paper. Position a rack in the center of your oven and preheat to 350°F.
2. Over a large bowl, sift together your flour, cornstarch, baking powder, baking soda, and salt. Set aside.
3. In a separate large bowl, cream together butter and sugar. Whip for about 2 minutes, or until you're left with a fluffy and pale mixture. Add eggs to the butter-sugar mixture one at a time, beating well after each addition. Add vanilla and stir to combine.
4. Alternate adding in dry ingredients and 1 & ½ cups milk, beating well after each addition until everything is just incorporated. Make sure to start and finish off with an addition of dry ingredients to avoid over mixing the flour. I like to do 3 additions of flour and 2 additions of milk.
5. Reserve approximately 1 cup of batter for the chocolate marble. Pour the rest of the vanilla cake batter into your prepared baking dish, and set aside.
6. Sift your cocoa powder into a small bowl, and add the remaining ¼ cup of milk. Whisk the two ingredients together until you get a smooth paste. Add this paste to the reserved cup of vanilla cake batter. Whisk until everything is incorporated.
7. Pour or spoon the chocolate batter across the vanilla cake batter in the pan. Using a knife or a skewer, swirl the batter into a marble effect by running a thin knife or skewer up and down the batter lengthwise, then again width wise.
8. Bake in the center of your preheated 350°F oven for 25 to 30 minutes, or until a skewer inserted in the center comes out clean. Cool completely to room temperature in the pan. Top with frosting, or slice and serve plain!
9. Enjoy!