This classic marble cake recipe is a perfect combination of vanilla and chocolate flavors. The cake is moist, tender, and has a beautiful swirl pattern. It's a great dessert for any occasion and can be enjoyed with a cup of coffee or tea. To make this cake, you'll need all-purpose flour, sugar, baking powder, salt, butter, eggs, milk, vanilla extract, and cocoa powder. The recipe is easy to follow and yields a delicious cake that everyone will love.