Preheat oven to 170°c and grease baking tin

Sift flour put aside

Beat sugar and margarine till fluffy and pale

Add eggs one at a time and mix till incorporated

Add vanilla essence and beat for 1min

Fold in the flour and milk gently make sure its combined

Divide your batter in two bowls. Add cocoa to one bowl

Pour batter into the baking tin, alternating the two mixtures creating patches

Bake for 40min or till ready

Remove from oven allow to cool for 15min in tin then remove and leave to cool completely