Combine the brown rice flour, cornstarch, tapioca flour, xanthan gum, salt and baking soda in a food processor. Blend on high speed for about 15 seconds. Set aside.
Beat the sugars and coconut oil in a large bowl for 2 minutes. Add the whole egg and egg yolk and the vanilla and beat until combined and the cookie dough is smooth.
Gradually add the flour mixture into the wet mixture and beat until combined. Stir in the chocolate chips (the dough will be very stiff).
Place 1½ inch cookie dough balls on a lined cookie sheet. (Recommended: [url:1]Silpat[/url]) Do not refrigerate the dough first or it will become very hard because of the coconut oil.
Bake the cookies for about 12 minutes or until light golden brown around the edges. Let cool on the baking sheet for 2 minutes before transferring to a wire rack.
Recipe by The Daring Gourmet at https://www.daringgourmet.com/perfect-gluten-free-chocolate-chip-cookies/