Preheat the oven at 180° and grease the baking tin or place a parchment paper or put butter and dust with flour

Mix melted butter, warm milk and vanilla and keep aside

Sift flour,corn starch,baking powder and salt and keep aside

Separate 3 eggs and add three whole eggs the yolk.add half the sugar gradually to the whites and beat till fluffy.add the rest of the sugar to the yolks and beat until fluffy also

Mix the egg mixture and fold in. Add the flour mixture and gently fold in.add the butter mixture and keep folding in gently.separate the batter into two equal portions then add coco powder and fold it in.

Using a spoon put each portion one after the other into the baking tin

One after the other until the batter is finished

Keep doing the same with the rest of the batter

Using a skewer or toothpick.make lines like this

Bake at 180° for 40 minutes or until a toothpick comes out clean decorate or serve with tea