I've found the recipe on here already but not the method. Can anyone tell me if it's a 2 layer cake or one? I last made it approx 10 years ago for youngest DS and cannot remember anything much about it except that it was delicious, easy and cheap for a chocolate cake! Have listed ingredients of recipe below in case this helps 
4oz self raising flour
1oz cocoa powder
1tsp baking powder
5oz unsalted butter
5oz golden caster sugar
1tsp vanilla extract
3 eggs
2tbsp cold water
For the icing:
5oz plain milk chocolate
5oz double cream