If desired, try one of these variations: Walnut-Orange: Add 3/4 teaspoon grated orange zest to the butter and 2/3 cup finely chopped walnuts to the flour. Pecan-Cinnamon: Mix 2/3 cup finely chopped pecans and 1 teaspoon ground cinnamon to the flour. Sprinkle the tops of the unbaked cookies with a mixture of 2 tablespoons granulated sugar and 2 teaspoons ground cinnamon. Almond: Reduce the vanilla extract to 1 teaspoon and add 1/2 teaspoon pure almond extract. Add 3/4 cup chopped toasted sliced almonds to the flour. If desired, brush the top of each unbaked cookie with some egg white and press a few un-toasted almond slices on the top.