Cream margarine and brown sugar until light and fluffy.
Add combined dry ingredients; mix well.
PRESS half of crumb mixture in GREASED 9 x 13 pan.
Spread with preserves...you can use 1 1/4 cups of homemade preserves also...use whatever you want to use up! I stir the preserves in a small bowl to make sure they are easily spread over the crumb mixture.
Sprinkle remaining crumb mixture over the top and press lightly.
Bake at 400 degrees 20-25 minutes. Cool and cut into bars.