Sift 2 cups flour and confectioners sugar together. Cut in butter or margarine until mixture clings together. Spray glass 13x9x2 with Pam and press dough into pan. Bake at 350 degrees F. for 20-25 minutes or until lightly browned.
Beat together eggs, granulated sugar, and lemon juice. Sift flour and baking powder; stir into egg mixture
Pour over baked crust. Bake at 325 degrees F. for 25 minutes more. Sprinkle additional confectioners sugar if desired. Cool. Chill in refrigerator for several hours or over night. Cut in bars.