Heat oven to 180c, grease and line a 20 round cake tin
Put all the ingredients except the cocoa in a bowl and mix ( using an electric mixer ) until combined and smooth
Take out half and put in another bowl. Sieve the cocoa into 1 bowl and mix it tgrough
Dollop alternate flavours of mix into the prepared tin . Tap the bottom of the ton to ensure the bottom is covered . With a skewer or knife swirl the mix to get a marble effect
Cook for 40-50 minutes , making sure a skewer comes out clean when inserted.
Cool on a rack