Crust - combine flour, powdered sugar and butter in a medium bowl, mix well and press into an 8 inch square baking dish. Bake 20-25 minutes, until lightly golden.
Filling - combine all ingredients in a large bowl, mix well. Spoon on top of crust and spread evenly. Bake 20-25 minutes, until golden brown. Cool completely on a wire rack before cutting.
Makes 16 bars.