Neapolitan Marble Sponge Cake

Today I woke up thinking about making a colourful cake and instantly neapolitan came to my mind.  This is a fun and festive-looking cake although it looks a bit naked without frosting ;-)   Anyhow, this cake is moist, soft and fluffy.  And it is so light that I gobbled up a few slices at one go (what a pig! Oink! Oink!)

Ingredients:

(A)
75g plain flour
10g corn flour
1/4 tsp baking soda
1/4 tsp salt

(B)
5 egg whites
1/4 tsp cream of tartar
80g caster sugar

(C)
5 egg yolks
1 tsp vanilla extract
60g Rice Bran oil
85g coconut milk

(D)
pink food colouring
1/2 tbsp cocoa powder

• Preheat oven to 160 deg C.  
• Sift all ingredients (A) together twice.  Set aside.
• Beat egg whites until frothy, add in cream of tartar and beat until soft peaks form.  Gradually add in sugar and beat until stiff peaks form.  Set aside.
• Mix egg yolks together with vanilla extract, oil and coconut milk until well blended.  Sift in flour mixture.
• Lighten the batter with a quarter of the meringue using a balloon whisk. Then pour the egg yolk mixture into the meringue and fold gently.
• Divide the batter into 3 portions.  Add in food colouring to one portion to tint the batter pink.  Sift cocoa powder into the second portion and stir to combine.  Leave the third portion plain.
• Drop large spoonful of each mixture alternately into an 8" (or 20cm) round cake pan.  Repeat with remaining batter, placing colours alternately on top of the first layer.  
• Bang the cake pan on the kitchen bench to remove large air bubbles.  Then, using a chopstick, swirl through the batter to create a marble effect.
• Bake the cake for 50 minutes or until cake is done.
• After removing cake from the oven, drop the pan onto the kitchen benchtop (this is to prevent cake from shrinking).
• Leave the cake to cool in the pan for about 10 minutes before unmoulding the cake.

NOTE:  I am using a removable bottom cake pan, so I didn't grease or line the pan at all.  If using a fixed bottom cake pan, just line the base.