¼cupunsweetened natural or Dutch-processed cocoa powder(25g)
2tbspwhole milkroom temperature
For the Chocolate Frosting:
¾cupunsalted butterroom temperature (170g)
8ounces1 block cream cheeseroom temperature (225g)
½cupunsweetened natural or Dutch-processed cocoa powder(50g)
Preheat the oven to 350F. Butter and flour 2 (8-inch) cake pans.
For the Vanilla Cake Batter:
In a large bowl, whisk together flour, baking powder, salt, and baking soda.
In a large mixing bowl or the bowl of a stand mixer fitted with the paddle attachment, beat butter on medium speed until creamy. Add the sugar and beat until light and fluffy, about 3 minutes. Add the eggs, one at a time, beating until well combined before adding the next.
In a large liquid measuring cup, whisk together the milk, sour cream, and vanilla.
With the mixer on low, add one-third of the flour mixture. Alternate with half of the milk mixture, and continue alternating with the remaining flour and milk mixture.
For the Chocolate Batter:
Place 2 1/2 cups of batter in a large bowl. Add the cocoa powder, milk, and sugar. Mix just until combined.
To Make the Layers:
Place a large spoonful of vanilla batter in the center of each cake pan. Place a large spoonful of chocolate batter in the center of the vanilla batter. Continue alternating spoonfuls of batter until all of the batters are used. Gently tap the pans on the counter to spread the batter to the edges of the pans, if needed.
Bake for 30 to 35 minutes, or until a wooden pick inserted into the center comes out with a few moist crumbs. Let the cakes cool in the pan for 20 minutes. Carefully remove and cool completely on a wire rack.
For the Chocolate Frosting:
In a large mixing bowl or the bowl of a stand mixer fitted with the paddle attachment, beat butter, cream cheese, and salt on medium speed until smooth and creamy, about 1 minute.
Sift the powdered sugar and cocoa powder into the bowl. Add the vanilla. Beat on low speed just until combined. Increase speed to medium and beat until light and fluffy, about 2 minutes.
For the Assembly:
Trim the tops of the cakes to create level layers, if needed. Place one cake layer on a cake stand or plate. Spread about ½ cup frosting over the top. Place the other cake layer on top. Spread the remaining frosting all over the top and sides of the cake. Make swoops with a spoon or offset spatula, or decorate as desired. Chill for at least 1 hour or until ready to serve.
Baking soda and baking powder play a crucial role in the cake rising, so make sure they have not expired before using them.
I prefer using high-quality Dutch-processed cocoa powder. Dutch-processed cocoa powder is darker and less acidic compared to regular cocoa powder.
When measuring the cake flour, I recommend using a scale for the most accurate measurements. However, if you don’t have one, make sure to fluff the flour first and then spoon it into your measuring cup. Level off the cup with the back of a knife to ensure you don’t overpack the flour.
The eggs should be at room temperature to ensure they evenly incorporate into your batter without accidentally overmixing. It’s also why we add them one at a time to the batter. If you forgot to bring out your eggs, you could quickly bring them to room temperature by placing the eggs in a large bowl and covering them with warm tap water for 5 minutes.
I usually recommend tapping the cake pans to pop air bubbles, I suggest doing so very gently as you don’t want to jostle the layers too much.
If you want to add a pop of color to the vanilla layer, you can use gel food coloring. Gel food coloring is more concentrated and doesn’t add additional liquid to the batter.