Combine 1 3/4 cups flour and 1/2 cup powdered sugar; cut in butter with a pastry blender or 2 knives until mixture resembles coarse meal. Press mixture into bottom of a 13- x 9-inch baking pan coated with cooking spray. Bake at 350° for 20 minutes or until crust is lightly browned; cool on a wire rack.
Combine remaining 1/2 cup flour and baking powder; set aside. Combine eggs, 1 1/2 cups sugar, lemon rind, and lemon juice; stir in flour mixture. Pour over prepared crust.
Bake at 350° for 25 minutes or until lightly browned and set. Cool on a wire rack. Dust lightly with powdered sugar; cut into bars.