Sponge for a mug or small jug Scale this up as necessary. Blend the sugar into the almost melted butter. Blend in the egg. Add the flour and mix well but stop once it's mixed. Bake or, for something more like a soufflé, microwave but be careful not to overcook. Test after one minute by stabbing with a skewer. If it comes out dry, it's cooked. Butter 60 g Caster sugar 60 g Self raising flour 60 g Medium egg 1 Optional goodies ... Chopped prunes Apple slices Chocolate chips Cocoa powder Sultanas Cranberries Blueberries Nuts