For sponge
Weigh however many eggs you want in their shells (2 eggs will do about 16 fairy cakes)
Use the same weight of marg, caster sugar & flour.
Mix the sugar & marg with a tsp opf vanilla, then gradually add in the flour & eggs
If you want extra's just stir in at the end (choc chips etc)
I bake at 200 c for about 15mins - til they spring back when you touch them