Spread the jam evenly between the tins. Cream the margarine and sugar together and then beat the eggs into the creamed mixture.
Sift the flour and baking powder together into another bowl and gradually add to the creamed mixture. Add sufficient milk to give a soft consistency. Divide the mixture between the tins and spread evening on top of the jam.
Bake in the preheated oven for 30-35 minutes until cooked in the middle. Allow to cool to 68c to ensure children do not burn their mouths.
Dust with icing sugar and serve hot with custard.
NB. Alternatively you could cook the sponge and cool it down, spread jam on top and sprinkle with coconut. (Please note that coconut is not a nut.)