This can be made with either lemon or orange juice, with equally good results. Very quick to do in a food processor.
115 g softened butter
115 g sugar
115 g flour
grated rind and juice of 2 lemons or 1 orange
1 tsp baking powder
For the icing:
1 large orange or 2 lemons
120 g icing sugar
Cream the butter and sugar together throroughly. Add the eggs one at a time, beating thoroughly each time. Add the flour, and the juice and grated rind, then the baking powder. Pour into a buttered cake tin and bake at 180 C for about 30 minutes, testing with a skewer to see if it’s done.
Meanwhile, dissolve the icing sugar in the orange or lemon juice by warming slightly. As soon as the cake is ready, unmould it onto a plate and pour over about half of this syrup. Leave to cool, then glaze with the remaining icing.