Preheat oven to 350 degrees and line two baking pans with silicone liners or parchment paper.
In a medium mixing bowl, whisk together the gluten free flour blend, baking soda, and salt until combined. Set aside.
In a large mixing bowl, use an electric hand mixer to cream together the butter and sugars until well combined.
Add the peanut butter to the sugar mixture and continue mixing until well combined. Mix in the egg and vanilla extract. Use a rubber spatula to scrape down the sides of the bowl and mix until completely incorporated.
Stir the dry ingredients into the wet ingredients until combined.
Use a 1.5-tablespoon cookie scoop to drop the dough, about 2-inches apart, on the prepared pans. Gently press a fork down on the top of each dough ball. Turn the pan and press down with the fork again, making a waffle pattern.
Bake at 350 degrees for 10-12 minutes or until the tops of the cookies are set. Allow the cookies to cool on the pan for 5 minutes before transferring to a wire rack to cool completely.
Notes
Check the ingredients of your gluten free flour mix for xanthan gum. If your flour mix doesn’t contain it, try adding ½ teaspoon to the recipe. I used Bob’s Red Mill Gluten Free 1 to 1 Baking Flour which contains xanthan gum.
Use a 1.5-tablespoon scoop to drop the dough on the prepared pans. The scoop allows you to use the same amount of dough for each cookie.
Leave the cookies on the pan for 5 minutes before moving them to a wire rack. The cookies are very delicate when they come out of the oven and they will easily break or crumble without the 5 minutes needed to cool and set up.