Preheat oven to 180 degrees, and grease the pan with oil and dust if off with some flour.

In a bowl put all dry ingredients (except the cocoa powder) and whisk them a bit.

Add butter mix until the dry ingredients are crumbly and looks like coarse of sand.

In another bowl whisk the eggs,milk,oil and vanilla until blended. Slowly add half of the egg mixture to the dry mixture until the batter becomes thick and fluffy.

In a separate bowl mix 3 tablespoon of cocoa powder with 2 tablespoon of hot water. Stir until smooth and set aside.

Put 1 1/2 cup batter into another bowl and stir in the chocolate mixture. Now it is time to marble the batter in to the baking tin.

Place 3 large spoonful of batter into the pan then 3 spoonful of chocolate batter. Repeat until all batter is on the baking pan. Do not mix.

Bake at 180 degrees for 30-35 minutes or until a toothpick inserted in the center comes out clean. Let it cool in the pan for 10 minutes the turn out. If you wist to decorate let it cool completely the decorate to your liking.