In a medium bowl, mix the softened butter with 3/4 cup of sugar.
Using an electric mixer, whisk the eggs with 1 cup of sugar.
Add the butter mixture into the egg mixture.
In a separate bowl, mix together the sour cream, baking powder, and baking soda. Add the sour cream mixture into the egg and butter mixture.
Working slowly, add the flour into the batter until well-combined. Next, split the batter in half in two separate bowls. Add cacao powder to one of the bowls to create the chocolate cake and whisk until well-combined.
Spray a 7-inch cake pan with cooking spray. Alternating the different colors of batter, place two tablespoon of batter at a time into the cake pan until you run out. This will create the zebra stripe effect.
Bake the cake at 350°F for 40 minutes. To check if the cake is done, stick a toothpick into the center. If it comes out clean, it's ready. Once the cake completely cools at room temperature, slice it into 2-3 equal sized layers with a serrated knife.