Lightly grease or spray a 20 cm dish.

Sift the flour, salt and baking powder into a bowl. Cream the margarine and sugar substitute together until light and fluffy. Add egg and vanilla essence. Stir in the oil and fold in the dry ingredients, adding sufficient water to bind the mixture.

Divide the dough in half. Place one half into the freezer to chill. Spread the remaining half onto the base of the prepared dish. Spread the jam
evenly over the dough. Grate the chilled dough to cover the jam.

Conventional:
Bake in a preheated oven 180C until golden brown about 30 minutes

Microwave:
Microwave on 70% power for 10 minutes. Place under a grill to brown.

Cut into wedges while still hot and serve with chilled custard sauce.