Combine dry shortbread ingredients and set aside; in large bowl combine vegetable shortening, vegan sugar, egg substitute, and vanilla, mixing well. Add dry ingredients and mix well. Pat the mixture evenly over the bottom of a lightly greased 9 by 13 glass baking pan. Bake in preheated 350 degree oven for about 10 minutes; cool in pan on rack.
Combine topping ingredients in a large bowl, in order listed, mixing well. When shortbread has cooled to room temperature, spread a layer of preserves over it ( about 1/4 does nicely),and then sprinkle with the topping; return to oven and bake for another 20 or 30 minutes, until topping is set. When cool, cut into bars (pan should net about 48).
The calorie count of these tasty bars may go through the roof, but they're so good that a day or two of diet penance is worth it!