Step 1 In the bowl of a stand mixer, or in a large bowl using a hand mixer, cream the butter, sugar and salt over low speed until combined and fluffy, about 3 minutes. With the mixer running, add the egg, beating until fully incorporated. Gradually add the flour and continue to mix until it forms a sandy texture. Form the dough into a disk and wrap in plastic wrap. Refrigerate until firm, at least 30 minutes.