Melt butter in a small pan. Beat eggs with sugar and vanilla extract using a mixer until fluffy.
Mix flour with baking powder. Add to egg mixture, alternating flour, sprite, and butter.
Divide batter into 2 parts. Add cocoa to one part and corn starch to second part.
Grease a 9 inch spring form pan. Pour batter with a tablespoon to the spring form pan starting with the white batter. On top of this batter, pour the dark batter with a tablespoon , and repeat until all the batter is gone.
Bake cake in a preheated oven to 335 F for 50 minutes or until wooden stick comes clean.