Preheat the oven to 350° F.
Using a pastry blender, combine the crust ingredients until the mixture resembles crumbs.
Using your fingers, press the mixture into a greased and floured 8? square glass baking pan (make sure that the entire bottom of the pan is evenly covered).
Bake partially for about 15 minutes, then remove from the oven.
While the crust is prebaking, combine the filling ingredients and pour over the warm crust.
Bake for about 15-20 minutes (or until lightly browned), being careful not to overbake.
Let cool completely.
Once cool, sift the powdered sugar over the top, according to your taste.
Slice into 16 bars and serve.