With just one batter to make, this easy marble cake is exactly that - easy! Chocolate and vanilla cake are marbled together and sandwiched between layers of vanilla buttercream. Then it's all covered up with chocolate buttercream. Yum!
How to mix this easy marble cake batter
Start by gathering your ingredients. Everything should be at room temperature which means taking your butter, eggs, and buttermilk out of the fridge at least two hours before you use them.
Mix the butter and sugar together on medium speed for about three minutes, until it gets much lighter in colour. It should look creamy and fluffy. Scrape down to the bottom of the mixing bowl to scoop up any sugar that the mixer hasn’t caught. Otherwise,you'll have lumps of gritty sugar in your batter.
Next add the room temperature eggs one by one, mixing for 30 seconds after each egg. Being at room temperature and adding them one at a time will help them incorporate easily into your batter. This makes the cake light and fluffy.
After the eggs comes the vanilla. Real vanilla instead of artificial vanilla will give you the richest flavour in your cake. Once that’s mixed in, you’ll need half of all of the dry ingredients. These are all-purpose flour, baking powder and baking soda. Pour this portion of the dry ingredients into the mixing bowl and mix at the lowest speed until you can’t see flour in the batter anymore. Scrape around the sides and bottom of the mixing bowl to mix in any flour clinging there. Then mix for a few more seconds, still using the lowest speed.
How to turn this batter into chocolate and vanilla
Now we’re going to divide the batter and there are three ways of doing this. You can weigh the batter, measure it with measuring cups, or guess/eyeball it! The most precise is to weigh the batterusing a scale until you get exactly half of the total amount. Set this batter aside to make the chocolate batter later, after you finish preparing the vanilla batter in the mixer.
Add buttermilk and oil to the vanilla batter in the mixer, mixing until everything’s incorporated. You really don’t want to overmix the batter after you’ve added any flour. Overmixing makes the cake dense and tough. Add a quarter of the dry ingredients, also mixing that only until it’s all incorporated. Now the vanilla batter is ready! Pour it into another bowl and then transfer the other half of the batter back into the mixer. This will be the chocolate batter.
To make the batter chocolatey we need cocoa powder, mixed with water to make quite a thick liquid. Whisk it together or use a fork to stir until the cocoa powder dissolves completely. The liquid should be smooth with no lumps.
It’s easiest for the cocoa powder to dissolve if the water is hot. If you do use hot water, wait for the mixture to cool before you add it to the batter.
Mix on the lowest speed until the cocoa mixture is incorporated. Then add the rest of the dry ingredients and mix on the lowest speed until those are incorporated. You’ll probably have to scrape down to the bottom of the bowl to gather up the flour stuck down there. Just like with the vanilla part of the batter, don't overmix after adding the flour. As soon as you don’t see any white specks of flour in the batter, turn the mixer off.
Marble the cake layers
Now that we have the vanilla and chocolate batter, let’s get this party started! Divide the batter between three cake pans which you’ve greased with an oil spray or butter. Alternate between the vanilla and chocolate batter in each pan. I like to use an ice cream scoop for this part.
To marble the batter, drag a toothpick or the end of a spatula back and forth through the batter. Make sure you push down to the bottom of the pan so the marbling goes all the way through the cake layers. If you’re using a toothpick or anything else really thin you’ll need to go back and forth in several directions to get a good marble effect. This will look stunning when we cut into it!
Bake the easy marble cake layers
Bake the cakes at 350F or 175C until the middle doesn't wobble when you shake the pans. To double check, stick a toothpick into the middle of each layer. f it comes out clean, the cakes are baked. If there are smears of raw batter on the toothpick, bake them for two more minutes before checking again.
When you take the pans out of the oven, let them rest in the pans for five minutes. This way they'll firm up slightly and won't crack when you turn them out of the pans. Turn the pans over to flip the cakes onto a wire rack to cool. If you leave them in the pans for too long the cakes will continue to bake and might stick to the pans as they cool. By turning them onto a wire rack they’ll cool more quickly because the rack allows air to go underneath them.
How to assemble this easy marble cake
After the cake layers cool you can level them if you like. This will make them completely flat and that will make for a prettier slice when you cut into the cake. To level the cake layers, slice around the top with a serrated knife like a bread knife.
As long as you don't overbake this cake, it is incredibly moist. It's not very sweet so you can use any filling and frosting without making it overly sweet. My favourite combination is vanilla buttercream for the filling between the cake layers and chocolate buttercream as the frosting. To make the buttercream, mix butter and powdered sugar together until smooth. Then add vanilla to flavour it and milk to thin it out slightly. Use about a quarter of it to fill the cake, saving about half a cup for decorations at the end.
To assemble the cake, spread or pipe a dot of buttercream onto a cake board. Press your first layer of cake into the dot. Spread or pipe vanilla buttercream onto the cake layer and then place another layer of cake on top. Repeat with another layer of filling and the third cake layer.
How to frost this easy marble cake
To make chocolate buttercream to frost the cake, melt chocolate chips in the microwave. Use 80% power for 30 seconds at a time so that the chocolate doesn't overheat and seize. Stir the melted chocolate until it's smooth and then let it cool before adding it to the remaining buttercream. Keep stirring until there are no streaks of melted chocolate in the buttercream.
To prevent crumbs in your frosting you can chill your cake layers in the freezer for 15 minutes before frosting them. This makes them firmer and less crumbly. I always recommend applying a crumb coat, which is a really thin layer of frosting to trap any the crumbs that come off the cake. By doing this before applying your final layer of frosting, no crumbs will get into the visible outer layer of frosting on the cake.
How to decorate the cake
As a finishing touch, show that there is both vanilla and chocolate inside this cake. Using the vanilla buttercream you set aside earlier,spread or pipe a thin layer around the bottom of the cake. Use the tip of your offset spatula to swipe the vanilla buttercream upwards in a diagonal all around the cake.
When you notice the frosting building up on your offset spatula, scrape it off into a bowl before you continue. You only need light pressure for this.I f you push so hard that you expose the chocolate frosting through the vanilla, just go over that area again and any buttercream on your spatula will cover it up.
Storing and serving this Easy Marble Cake
You can store this cake for two days in the fridge but it tastes best at room temperature. If you refrigerate it, I recommend taking it out of the fridge 2-4 hours before serving.
Now let’s cut into this beauty! Look at that beautiful marbling!
I hope you love this Easy Marble Cake as much as I do! If you make it, please leave a review and tell me what you think in the comments!
You'll find the recipe for this Easy Marble Cake below, with measurements for the ingredients in cups and also in grams. Switch between units of measurement by clicking the "US" (for cups) and "M" (for metric grams and ml) at the top of the recipe. You can adjust the recipe to make larger cakes by clicking the "1X" for a six inch cake or "2X" for an 8 inch cake.
In this one-batter recipe, chocolate and vanilla cake are marbled together and sandwiched between layers of vanilla buttercream, covered with chocolate buttercream. Yum!
For the cake batter:
1 1/2cups granulated sugar
1 tablespoon vanilla
1cup all-purpose flour
1 1/2 teaspoons baking soda
1/2 teaspoon baking powder
1/8 teaspoon salt
For the vanilla batter:
2 tablespoons vegetable oil
1/2cup all-purpose flour
For the chocolate batter:
1/3cup cocoa powder
3/4cup hot water
1/2cup all-purpose flour
For the filling and frosting:
1 1/2cups unsalted butter at room temperature
4cups powdered sugar
1 teaspoon vanilla extract
1/2 teaspoon salt
1-2 tablespoons milk or cream
1/3cup chocolate chips
To make the marble cake layers:
In a bowl, whisk together hot water and cocoa powder until the cocoa powder has dissolved. Set aside to come to room temperature.
In a mixer with a beater attachment, mix butter with sugar on medium speed until pale and creamy, about three minutes. Scrape down to the bottom of the bowl once during mixing to make sure no butter or sugar is stuck at the bottom.
Add eggs one at a time, mixing on the lowest speed after each egg until incorporated, about 30 seconds.
Add vanilla and mix on lowest speed for about 30 seconds to combine.
In a bowl sift and whisk together 1 cup flour with baking soda, baking powder and salt. Add to the mixing bowl and mix on the lowest speed to incorporate.
Pour or scoop half of the batter into a separate bowl. You can pour it straight into a measuring jug (it will be be 1 1/3 cups batter) or into a bowl on a scale (it will weigh 325g). Set this aside to make the chocolate batter later.
Add the buttermilk and oil to the mixing bowl and mix on the lowest speed to combine. Add 1/2 cup flour and mix on the lowest speed until you can't see flour in the batter, about 30 seconds.
Grease three cake pans and divide the vanilla batter between them, using an ice cream scoop or spooning it into blobs spread out around each pan.
Pour the set-aside batter back into the mixing bowl and add the cocoa powder mixture. Mix on the lowest speed to combine. Add 1/2 cup flour and mix until batter is smooth, about 30 seconds.
Using a measuring cup or ice cream scoop, divide the chocolate batter between the pans by adding it in blobs in between the vanilla batter. Use the handle of your spatula or a toothpick to swirl the batter, going all the way down to the bottom of each pan. Tap each pan on the counter to knock any air bubbles out of the batter.
Bake at 175ºC or 350ºF for 26 minutes or until a toothpick inserted into the middle of the cake comes out clean.
Let cakes cool in their pans for 5 minutes. Use a spatula to loosen cake from the edges of the cake pan and then turn onto a wire cooling rack. Leave to cool completely.
To make the frosting:
Mix butter and powdered sugar on the lowest speed until smooth. Add vanilla, salt and milk and mix to combine.
Heat the chocolate chips in the microwave at 80% power for 30 seconds at a time, stirring after each time, until smooth. Set aside to cool.
To put it all together:
Spread a dot of buttercream onto the middle of a cake board and press your first layer of cake onto it. Spread vanilla buttercream onto the first layer of cake and place the next layer on top. Repeat with another layer of filling and the final cake layer.
Set aside 1/2 cup of vanilla buttercream. Add the cooled melted chocolate to the rest of the buttercream, stirring until there are no streaks of melted chocolate in the buttercream.
Frost the cake with chocolate buttercream, applying a thin layer first (a crumb coat) and letting it set at room temperature for 30 minutes or in the fridge for 15 minutes before applying a final layer.
As soon as you've finished frosting the cake, use the remaining vanilla buttercream to spread or pipe a thin layer around the bottom of the sides of the cake. Using gentle pressure, rest an offset spatula or the back of a spoon on the cake board and drag it diagonally upwards to create texture in the vanilla buttercream, repeating the motion all around the cake.
You can refrigerate this cake for two days after making it.
This cake is best served at room temperature! If you refrigerate it, take it out of the fridge 2-4 hours before serving it.