Add the gluten free flour and salt to a small bowl and whisk together. Then set aside.

Add the butter, powdered sugar, and vanilla extract to the bowl of a stand mixer fitted with the paddle attachment. Mix until combined and smooth.

Scrape down the bowl and add the flour mixture. Mix on low speed until combined, scraping down the bowl as needed.

Transfer the dough to a piece of plastic wrap (or wax paper) and shape into a rectangle that measures 7x2.5x1 inches (approximately). Wrap in the plastic wrap and use it to help smooth the sides. Refrigerate the dough for 2 hours.

Once the dough has chilled for 2 hours, slice the cookies 1/4 inch thick and place on a half sheet pan lined with parchment paper. Use a fork to gently prick holes on each end of the cookies. Place the cookie sheet in the freezer for 20 minutes before baking.

Preheat oven to 350 degrees and line a second half sheet pan with parchment paper.

Bake the cookies (12 per pan) for 10-11 minutes or until the edges are set and not quite golden. Cool the cookies on the pan 10 minutes before removing and cooling completely on a wire rack.