In the bowl of a standing mixer, cream the butter and powdered sugar until light and fluffy.
Beat in the vanilla, flour and salt. Shape the dough into two disks, wrap in plastic and refrigerate for 30 minutes or until firm enough to roll.
Preheat the oven to 325°F.
On a well floured surface, roll the dough out to about ¼ inch thickness.
Using a 2 inch round cookie cutter, cut as many cookies as possible. Re-roll and cut until all of the dough has been used.
Place the cookies on a cookie sheet, sprinkle with the Demerara sugar and bake for about 20 minutes or until the cookies just begin to turn a light golden color.
Cool on wire racks.
Recipe by Culinary Thymes at https://www.culinarythymes.com/shortbread-cookies/