This is definitely the best sponge cake around. The family has reached a consensus.
3/4 cup sugar
1 cup flour
pinch of salt
1.5 teaspoons baking powder
4 tbls butter
2 tbls milk
2 tbls water
Set the oven to 200 C.
Beat together the sugar and eggs for 10 minutes until thick and frothy. (most important part!)
Sift together the flour, salt and baking powder.
Bring water up to the boil.
Very gently, mix the flour into the egg mixture, alternately with the butter mixture.
Oil the cake tin(s) and cut greaseproof paper circles for the bases.
Pour into one or two cake pans.
Place immediately into the oven.
Bake for 15 minutes for 2 small cakes, or 25 minutes for one large cake.
For a chocolate cake, take out a couple of tablespoons of flour and replace it with cocoa.
Passionfruit icing is delicious.