Beat together 1 cup butter, lemon extract, and lemon rind until creamy. Beat in egg.
Combine 1 cup powdered sugar, flour, salt and baking powder. Stir into creamed mixture or beat in with a mixer until a sticky batter forms.
Wrap in waxed paper. Chill freezer for about 30 minutes or cover batter in bowl and chill in refrigerator until ready to make cookies.
Shape into 1-inch balls. Place on lightly greased cookie sheets about 2 inches apart. Bake at 350 degrees for 12 minutes until firm. Cool a minute before removing to a rack to a rack to cool.