sifted all purpose flour
Combine butter, 1 cup flour and confections sugar in bowl; mix until crumbly. Press into ungreased 8-inch square pan. Bake in 350 oven for 8 minutes or until golden brown. Cool in pan on rack.
Combine sugar, 2 tbsp. flour and baking powder in bowl. Add eggs, lemon juice and rind. Mix well. Pour evenly over baked, cooled crust.
Bake in 350 oven for 25 minutes. (Top puffs up in baking, but falls in cooling.) Cool in pan on rack and cut into 2-inch squares. Sprinkle with confectioners sugar.