Marble Cake
A true showstopper, this marble cake has stunning swirls of chocolate and vanilla cake throughout each layer. Soft and moist, packed with flavor, and so much fun to make and slice into!
Servings 15 slices
Ingredients
Vanilla Batter
- 2 3/4 Cups (290g) sifted cake flour DIY recipe in notes
- 2 tsp baking powder
- 1/2 tsp baking soda
- 1 tsp salt
- 3/4 Cup (170g) unsalted butter, room temperature
- 1 1/2 Cups (300g) granulated sugar
- 2 large eggs + 2 large egg whites, room temperature
- 1 Tbsp pure vanilla extract
- 1/2 Cup (120g) sour cream, room temperature
- 1 Cup (240ml) whole milk, room temperature
Chocolate Batter
- 1/4 Cup (22g) sifted unsweetened natural cocoa powder
- 1 1/2 Tbsp (19g) granulated sugar
- 1 1/2 Tbsp whole milk, room temperature
- 3/4 tsp instant coffee or espresso powder (optional)
Chocolate Buttercream
- 2 Cups (452g) unsalted butter, room temperature
- 6 Cups (720g) powdered sugar
- 1 Cup (90g) natural unsweetened cocoa powder
- 6 Tbsp whole milk, room temperature
- 4 tsp pure vanilla extract
- 1/4 tsp salt
Instructions
Make the Vanilla Batter
- Preheat the oven to 350°F/177ºC. Prepare three 6-inch or two 8-inch cake pans by spraying the sides with a cooking spray (Baker's Joy is my favorite) and fitting a parchment paper circle to the bottom of the pan.
- Add the sifted cake flour, baking powder, baking soda, and salt into a bowl and whisk to combine. Set aside.
- In the bowl of your stand mixer (a handheld mixer works fine too!), beat the butter on high for two minutes until it's light and creamy. Add in the sugar and continue to mix on medium-high for another two minutes. Turn the mixer to low and add the eggs and egg whites, one at a time, mixing until just combined and scraping down the bowl and paddle as needed. Add the vanilla and sour cream, turn the mixer to high, and beat for one full minute. It will look curdled at this point, but don’t worry – it will become smooth cake batter at the end.
- Add in the dry ingredients all at once and turn the mixer to low speed. Mix until just combined, then slowly pour in the milk. Continue to mix on low speed until just combined, about 30 seconds. Scrape down the sides and bottom of the bowl and give it a few stirs with a whisk to make sure there are no lumps. The batter will be slightly thick.
Make the Chocolate Batter
- There will be around 6 cups (1300g) of vanilla batter total. Transfer half of the batter (650g) into a medium bowl and whisk in the 4 chocolate batter ingredients until smooth.
- Drop large spoonfuls of the vanilla and chocolate batters amongst each prepared cake pan. Repeat until all the batter is used, then use a wooden skewer to swirl the batters into a marble effect.
- Bake for 30-35 minutes. The cakes are done when a toothpick inserted in the center comes out clean. Let the cakes cool in the pan for five minutes before turning them out onto a wire rack for an additional few hours of cooling.
Make the Chocolate Buttercream
- In a stand mixer fitted with a paddle attachment, whip the butter on medium-high speed until creamy and light in color, about 5 minutes.
- Scrape down the bowl and paddle, then add powdered sugar, cocoa powder, milk, salt, and vanilla extract. Cover the mixer with a clean kitchen towel (to prevent ingredients flying out of the bowl), then turn the mixer to low and mix until all ingredients start to come together.
- Remove the kitchen towel, scrape down the bowl and paddle, then continue mixing on low speed until uniform and smooth, 2-3 minutes.
Assembly
- Once the marble cakes are completely cooled, level them to your desired height. Add a swipe of chocolate buttercream onto a cardboard cake circle and place the first cake layer on top. Fill and stack the cake with chocolate buttercream, then crumb coat the cake with chocolate buttercream. Place the crumb coated cake in the refrigerator for at least 30 minutes to let the buttercream set firm.
- To create the design pictured, reserve about 1/2 Cup of the remaining chocolate buttercream for the piping on top of the cake, then use the rest of the buttercream to frost the cake. Use a cake comb to create the scalloped texture, then place the cake in the refrigerator for another 30+ minutes to let the frosting firm up.
- Place all of the remaining chocolate buttercream into a piping bag fitted with Wilton tip 1M and pipe swirls around the top of the cake. Place marbled chocolate decorations in between each swirl (see blog post above for instructions on how to make the marbled chocolate decorations).
Notes
DIY Cake Flour Recipe: To make your own cake flour, spoon and level one cup of all-purpose flour and remove 2 Tbsp. Add 2 Tbsp of cornstarch. Repeat per the amount of cake flour you need, then sift the flour and cornstarch mixture 4 times (don’t skip that step!). After sifting, spoon and level to re-measure the amount of cake flour you need.
Make Ahead Tips:
- The marble cake layers can be baked ahead and stored at room temperature, wrapped in plastic wrap, for up to two days. Alternatively you can store the cakes in the freezer for up to two months.
- The chocolate buttercream can be made ahead and stored in an airtight container in the refrigerator for up to two weeks. When you’re ready to use it, bring it back to room temperature and re-mix in your stand mixer to bring it back to smooth buttercream consistency.