There are many recipes and variations to choose from, but the basics remain the same. Cream together butter and sugar until light and fluffy. Fold in cake flour, ground pecans, any essence of your choice, and mix until a dough is formed. Chill the dough. Roll the dough into balls and gently flatten, pressing a pecan into the middle of each cookie. Bake, coat with powdered/icing sugar, and prepare for bliss.