Melt in your mouth, simple and easy shortbread cookies are one of those Christmas staples that everyone must try. This recipe gets its perfect texture from just four ingredients: butter, icing sugar, flour and cornstarch. And, because they are rolled and cut with a cookie shape of your choice, you can make them plain, topped with candied cherries, drizzled with chocolate or mix the dough with chopped dried fruit or nuts before rolling. Enjoy the versatility of this basic shortbread dough and keep it in mind for all your special occasions.