Seperate 4 eggs, beat egg whites with 1 teaspoon baking powder under it forms stiff peaks.
Mix 1⁄2 cup oil and 1⁄2 cup boiling water with 2 tablespoon cocoa powder. Beat together with egg yolks and 1 cup castor sugar. Add 1 1⁄2 teaspoon baking powder and 1 cup flour and beat until combined.
Fold in the egg whites lightly with a metal spoon to avoid knocking the air out.
Pour batter into greased cake tin and bake on 180 degrees in a pre heated oven for about 35 minutes or until a skewer comes out clean.
For the ganache: Melt 1 slab of Cadbury dairy milk chocolate, add 1 small tine Nestlé cream and mix well. Spread over cake and decorate as desired.