Preheat the oven to 180 degrees C.
Grease and line a 9inch cake pan.
Sift flour and baking powder together and set is aside.
Beat together eggs and sugar until light and frothy.
Add in vanilla, oil and milk, beat well until well blended.
Now add in flour in 3 to 4 intervals and beat well.
Divide the batter into 2 bowls.
Add in the coco powder in one of the bowls and beat well.
Spoon about 3 tbsp of vanilla batter in the center of the pan.
On top of vanilla batter add 3 tbsp of chocolate batter and go on.
Donot stir, shake or swirl, the batter will spread by itself as you go on.
Serve the cake with some chocolate sauce drizzled or like my favorite way with some fresh whipped cream.