A light, crisp fatless sponge is one of the easiest cakes to make, especially if you use a hand-held electric mixer.
Usually only plain flour is used for making this style of cake. If you use self-raising flour, the cake can rise too much and then collapse. For a more exotic flavour, fold in 1tablespoonrosewater or orange flower water along with the flour.
Preheat the oven to 160°C, 325°F, Gas Mark 3. Brush a 20cm (8in) deep cake tin with oil or melted butter, then flour the base and sides well, shaking out the excess flour.
Beat 3 eggs with 125g (4oz) vanilla caster sugar in a heatproof howl over simmering water using an electric mixer or rotary heater, until the mixture is voluminous, pale and thick and leaves a trail when the heaters are lifted. It is important to have a firm foam. Do not let the bottom of the bowl touch the water.
Remove the bowl from the heat and beat the mixture for 2 minutes more. Very gently, using a large metal spoon, fold in 125g (4oz) sifted plain flour. Pour the mixture into the prepared tin and bake for about 45 minutes until the top is a golden colour and springs back when lightly pressed with a fingertip.
Cool the sponge in the tin for 5 minutes, then turn out and place base-side down on to a wire rack to cool completely. Cut in half horizontally with a long serrated knife, then sandwich together with jam and whipped cream or crushed fresh fruit. Dust the top with finely sifted icing sugar, just before serving, if desired.
Use the whisked sponge mixture to make a flan case for fruit. Grease and flour a 20cm (8in) sponge flan tin. Make up a reduced quantity mixture of 2 eggs with 75g (3oz) each of caster sugar and plain flour as in step 1. Bake for 25-30 minutes as in step 2, then cool as in step 3. Fill with fresh fruit and brush on a glaze with melted jelly.