Cream together butter and sugars; add egg and beat well. Sift together dry ingredients. Stir into creamed mixture. Add nuts. Shape in rolls about 2 1/2 inches across. Wrap in waxed paper and chill thoroughly. Slice very thin, 1/8 inch or less. Bake 1 inch apart on lightly greased cookie sheet at 375°, 5 to 7 minutes or until delicately browned. Remove at once to rack. Makes 5 to 6 dozen.