Preheat oven to 350 degrees F (175 degrees C). Grease and flour two 9 inch round pan
In a medium bowl, cream together the sugar and butter.
Beat in the eggs, one at a time, then stir in the vanilla.
Combine flour and baking powder, add to the creamed mixture and mix well.
Finally stir in the milk until batter is smooth. Pour a little batter into pan, drop chocolate cake balls, then pour the rest of vanilla batter covering the chocolate balls
Bake for 30 to 40 minutes or until knife inserted comes out clean