All-in-one Orange Sponge Cake Recipe

I00 g/4 oz butter or margarine, softened
100 g/4 oz caster (superfine) sugar
100 g/4 oz/1 cup self-raising (self-rising) flour
2.5 ml/0.5 tsp baking powder
Grated rind of 1 orange
15 ml/1 tbsp orange juice
2 eggs

Method:

Blend together all the ingredients until well mixed. Spoon into a greased and lined 20 cm/8 in cake tin (pan) and bake in a preheated oven at 180°C/350°F/gas mark 4 for 30 minutes until well risen and springy to the touch.