Blend butter, 1/2 cup powdered sugar and 2 cups flout to make a soft dough. Press evenly into ungreased 9 X 13 inch pan. Bake 15 to 20 minutes until golden brown.
Meanwhile, combine eggs, lemon peel, lemon juice, sugar and 1/4 cup flour and blend until smooth. Pour over baked crust.
Reduce heat to 325 degrees and bake 25 minutes until firm.
Cool. Dust with powdered sugar and slice into bars.