In a bowl add in ur cocoa powder pour boiling water in to the cocoa stir until smooth and it will thicken add sugar and stir it add in vanilla,baking soda stir and set aside.

In another bowl add in flour,baking powder,sift and set aside

In a mixing bowl add in butter and sugar cream until light and fluffy

Beating in eggs 1 by1 until smooth. add vanilla and beat until smooth

Add in half of the flour and beat on low speed,add in milk and beat until Incorporated

Add in the remaining flour and beat on low speed until smooth

Divide the batter mixture in to 2

Put in the half of batter mixture in to the cocoa use spatula stir until combined

Pour in your dark cocoa mixture in to the greased 8 inch square pan and level it and hit the pan

Gently spoon the batter over the cocoa layer and level it

Bake for 1hour or until skewer comes out clean.