I use 10oz of self raising flour, 6oz of sugar, 1/2 pint of milk and 1/4 pint of veg oil, pinch of bicarb. Makes quite a runny batter, so needs a good whisk, and doesn't keep as well as normal sponge. Very quick and easy to make.
Either makes muffins, cupcakes, victoria sandwich tins or even enough for a traybake sized sponge.