Preheat oven to 180 degrees C. Grease a 23cm square cake tin. Line the bottom of the pan with wax paper, or dust lightly with flour.
Sir together flour, baking powder, salt and spices.
In a large bowl, cream margarine. Blend in brown sugar, beating until light and fluffy. Beat in eggs and vanilla. Stir flour mixture into creamed mixture alternately with apple sauce; make 3 dry and 2 liquid additions, combining lightly after each. Turn batter into prepared pan.
Bake for 40 to 45 minutes, or until cake springs back when lightly touched.