1. Grease a 24cm springform tin and cover base with vegetable cooking spray.
2. Mix cocoa and boiling water in a cup, cool.
3. Cream butter and sugar until light and fluffy, then add eggs one at a time and beat well.
4. Sift flours with baking soda and stir into creamed mixture then add milk and vanilla. When well mixed, gradually stir in cocoa mixture. (The cake batter sometimes curdles at this stage, but it won't spoil the finished cake).
5. Pour into prepared tin and bake for 50-60 minutes.
6. Let stand for 5 minutes. Run a knife around edge and release sides of tin.
7. Turn carefully on to a cake cooler and remove base and paper.
8. When cool, ice.
CHOCOLATE GANACHE 150g dark chocolate, grated 1/2 cup cream Over low heat, melt chocolate in the cream. Remove from heat and cool. Pour ganache over cake and smooth with a flat-bladed knife. Try not to handle for too long. Allow to set.