1. Crack the eggs into a jug and beat.

2. In a bowl, cream together the caster sugar and margarine using a fork.

3. Sift together the flour and cocoa powder, mix 1/3 into the creamed sugar and marg, the beat in 1/3 of eggs, repeat until all the flour/cocoa powder and eggs are used up. Add a few drops of black food colouring to darken the cake.

4. Grease and line a square baking tin (around 10 inch), pour in the cake batter and bake in a preheated oven on gas mark 5 for 30-40 mins until cooked through (a skewer pushed into the middle should come out clean)

5. Once cooked, allow to cool and remove from the tin then allow to go completely cold.

6. Split the icing sugar equally into two bowls, add about 10ml of water to each and a few drops of each colouring to each separate bowl, add the water slowly as you want the icing to be quite thick and not too runny.

7. Once the icing is a paste sort of consistency and one is bright red and the other green, flood one half of the cake in one colour and the other side in the second colour, drizzle a couple of lines of the opposite colour over each side, and then pull a cocktail stick all the way across to make a pattern.

NB: If you like you could make this a vanilla sponge, switch the cocoa powder for extra flour. If you don't want it Halloween themed you can change the colourings.