Sieve maida with baking powder and baking soda at least twice and keep aside.
In a bowl Cream the butter and sugar till light and fluffy. Add milk and mix well until creamy.
Add vanilla essence, condensed milk / milk powder and give a quick stir. Then add maida, mix well to form a creamy batter.
Take 1/4 of the prepared batter, add coco powder and hot water, mix well and keep aside. Now your both the batters are ready.
Preheat oven to 170C for 10mins.
Meanwhile grease a baking pan(I used my bread loaf pan) with butter and flour.
First pour half of the vanilla batter and add half of the chocolate batter in circles. Then with a fork make marble like patterns – don't overdo.
Again add the remaining vanilla batter , chocolate batter in circles and make marble like patterns with a fork / knife. Can you see the swirls?
Now bake the cake at 170 deg C for 40-45 mins or until a fork inserted at the center of the cake comes out clean.
Cool down the cake for 10mins then invert.
Cut down into slices and enjoy Marble Cake!