sifted powdered sugar
Preheat oven to 375. Cream butter, add sugar and mix until fluffy. Fold in flour and cornstarch. Refrigerate for 30 minutes. Form into 1" balls.
Arrange 2" apart on cookie sheet. Flatten with bottom of sugared glass. Bake for 10-12 minutes or until edges are lightly brown.
ICING: Cream butter and gradually add powdered sugar, beating until fluffy. Beat in lemon juice. Ice cookies when cool.