Cream butter, icing sugar & custard powder
Add sifted flour & cornlour & mix to a soft dough.
Cover with clingwrap & chill 30 minutes.
Divide dough in half. Press one half into a
greased square or rectangular pan.
Spread with jam. Grate remaining dough over.
Bake @ 180*C for 15-20 minutes or unil golden.
Leave to cool then cut into squares. Sift icing
sugar over before serving.