Beat the butter and sugar together until light and creamy. Beat in the egg and lemon rind. Stir in the self-raising flour and the milk.
Place the jam in the base of a well-greased steamed pudding basin or heat-proof bowl and spoon the batter on top.
Cover with two layers of baking paper and secure with string. Sit the pudding bowl on a trivet or saucer in a large saucepan. Pour enough boiling water around the sides of the bowl for it to come three quarters of the way up the side of the bowl. Cover the saucepan and simmer for 1 hour to steam the pudding.
Turn pudding out onto a serving plate and serve with whipped cream, yoghurt or ice cream.
You can cook this without a steamed pudding basin. A stainless steel bowl or ovenproof glass bowl will also work.