Step 1

Beat butter, sugar and egg in a small bowl with an electric mixer until combined and stir in sifted flours. Spread the mixture over the base of a greased 19 cm x 29 cm rectangular slice pan and bake in a moderate oven for 10 minutes.

Step 2

To make the topping, combine all ingredients in a medium bowl and mix well.

Step 3

Spread the hot base with jam, then topping. Bake in a moderate oven for a further 30 minutes or until browned. Cool in pan.