Add all ingredients for the shortbread cookies to a mixing bowl and stir well until a thick, sticky dough forms.

Form the dough into a log shape and vacuum seal or wrap tightly with plastic wrap. Chill in the refrigerator at least 2 hours, or freeze at least 15 minutes.

When ready to bake, preheat the oven to 350 degrees F and line a large baking sheet with parchment paper.

Unwrap the dough and place on a cutting board. Use a sharp knife to cut slices of dough.

Place dough slices on the parchment-lined baking sheet and bake 12 to 18 minutes, until cookies are slightly golden on the outside.

Remove cookies from the oven and allow them to cool on the baking sheet completely before serving.