1. Preheat oven to 350°.
2. Weigh or lightly spoon 6.75 ounces (about 1 1/2 cups) flour into dry measuring cups; level with a knife. Combine 6.75 ounces flour and 1/2 cup powdered sugar in a large bowl, stirring with a whisk. Work in butter with hands until mixture resembles coarse meal that comes together like dough when pinched. Press mixture into bottom of a 13 x 9inch baking pan coated with cooking spray.
3. Bake at 350° for 15 minutes or until golden brown. Cool 5 minutes on a wire rack.
4. Combine granulated sugar, 1 1/2 tablespoons flour, and lemon rind in a medium bowl, stirring with a whisk. Add lemon juice and eggs, beating with a whisk until blended; pour over crust.
5. Bake at 350° for 20 to 25 minutes or until filling is set. Cool completely. Sift 2 tablespoons powdered sugar over top. Cut into bars.