IngredientsMaida-3 cupsButter-1 cup
Sugar-2 cups
Eggs-5
Milk-1 cup + 1tbsp
Baking powder- 1tsp
Baking soda-1/2tsp
Unsweetened cocoa powder-1/4 cup
Vanilla essence-2tsp
Salt-1/2tsp

Method
Pre heat oven to 350 deg. C.In a bowl mix maida,baking powder,baking soda & salt,keep it aside.Cream butter,essence & sugar well with a hand mixer.Add the eggs one by one & beat it well.In low speed slowly start adding the dry mixture alternating with milk.Take our 4 to 5 spoons of this cake batter into a bowl & add the cocoa powder to it.Add 1 tbsp of milk & mix it till smooth.Spoon the plain cake batter into a pan which is greased with butter and coat it with little maida and dust out the excess.Using the cocoa mixed cake batter make 3 strips on the cake as shown in the picture above.Now take a knife & gently draw swirls through the batter to marbleize it .Bake it for 50 minutes or till done.Cool completely before cutting.
Courtesy:Kavya with a slight change.............