Sponge Cake with Nuts and Cherries

• 225g (5oz) butter or margarine
• Finely grated zest of 1 lemon

Cream together the butter or margarine with the lemon zest and caster sugar until the mixture is really light and fluffy. You can employ your hand-mixer to do the job instead, if you prefer. Sift together the flour and salt. Beat the eggs into the creamed mixture gradually, adding a little flour as you go along to prevent the mixture from curdling.

Fold in the rest of the flour with a m