Traditional style gluten free shortbread made with only five ingredients: gluten free oat flour, butter, vanilla, sugar, and salt. Pure and simple, with a perfect crunch and a tantalizingly buttery aroma.
Preheat the oven to 350 F. Line two baking sheets with parchment. Whisk together the sugar, flour, and salt in a large mixing bowl.
Add the butter to the mixing bowl and drizzle the vanilla over the butter. Mix with a fork (or "cut in") until a dough forms. Note: if the butter is a bit cold, the ingredients will not become a dough until you knead them together with your hands.
Roll out the dough to a thickness of 1/3 inch. Cut out rounds with a 1 3/4 inch cookie cutter. Note: if the dough is too soft to cut cleanly, refrigerate it for a 15 minutes or so until it firms up.
Place the rounds evenly and equally between the two baking sheets. Keep in mind that the cookies will spread slightly. Sprinkle turbinado sugar on top of each cookie round, then bake the cookies for 13 minutes.
Remove from oven and let cool completely. As soon as the cookies are completely cool, store them in an airtight container.