Preparation / Directions:
Preheat oven to 350. Prepare a 8" baking pan with cooking spray and flour; set aside. In a mixing bowl, combine 1 cup flour, margarine, and 1/4 cup granulated sugar until mixture resembles coarse crumbs. Press into prepared pan. Bake for 15 minutes. Meanwhile, to prepare topping, combine remaining granulated sugar, egg whites, lemon juice, remaining flour, lemon peel, and baking powder in a mixing bowl. Pour mixture over baked crust. Bake again for 20 minutes or until lightly browned. Sift powdered sugar over top.