In a stand mixer fitted with a paddle attachment, beat butter and vanilla extract until creamed.
Add confectioners sugar and salt; mix until combined.
Scrape bowl down and add flour while beating on low. Scrape bowl once more and mix until combined.
Shape the dough into a rectangular prism, wrap in plastic and chill until firm. At least an hour.
Preheat oven to 350F (177C). Use a sharp knife to cut ½ inch thick slices
Place slices, spaced at least an inch apart onto a baking sheet lined with a silicone mat or parchment paper.
Use a fork or skewer to indent a pattern onto the top.
Bake for about 10 minutes, rotating baking sheet in the oven halfway through.
Transfer to a wire sheet to cool.