How can a cookie with only four ingredients taste SO good? All I had the energy to do on last Friday was bake a batch of shortbread. It was definitely a sick day! But shortbread is a wonderful starting point for all kinds of sweet adventures: one part sugar, two parts butter, three parts flour, no leavening. Oh, flavor it with pecans or hazelnut and a little powdered sugar to top it off. Simplicity never tasted so good.