Preheat oven to 180 degrees or 350 degrees F and grease your pan.

Sift your flour and castor castor sugar. Mix with a whisk.

Melt your butter or margarine. It should not be too hot

Beat your eggs and vanilla essence in a different bowl till frothy

Add your melted butter to the eggs.

Create a hole in the middle of the flour mixture.

Pour in your wet ingredients and gently fold the mixture, a little at a time. Use a spatula for best results

Add the milk to the mixture. Be careful not to over-fold the mixture.

Divide your batter into two. In one mixture add the cocoa powder.

Spoon half of the vanilla batter into the baking tin, followed by 2/3 of the cocoa powder mixture. Add the rest of the vanilla batter and finish with the cocoa batter mixture.

Place it in the second oven rack at the middle for 45-55 minutes.

For the icing, mix the icing sugar, green food color, and butter till stiff. Use a spatula or knife to apply on top of the cake. Add some sprinkles.