Preheat oven to 375 degrees F. In a mixing bowl, whisk together rice flour, potato starch, tapioca flour, xanthan gum, baking soda, baking powder, and salt for 30 seconds, set aside.
In the bowl of an electric stand mixer fitted with the paddle attachment, blend together butter, brown sugar and granulated sugar until mixture is well blended and creamy (if you aren't using a beater blade, the paddle attachment that scrapes the bowl while mixing, then occasionally scrap down sides and bottom of bowl throughout entire mixing process).
Mix in eggs one at a time, blending until combined after each addition. Stir in vanilla.
With mixer set on low speed, slowly add in dry ingredient and mix until combined. Mix in chocolate chips.
Drop dough (I shaped into balls for more even rounds) about 2 1/2 Tbsp (45g each) at a time onto Silpat or parchment paper-lined baking sheets, spacing cookies 2-inches apart.
Bake in preheated oven 9 - 11 minutes until golden. Sprinkle tops with Maldon Sea Salt if desired, and cool on baking sheet several minutes then transfer to a wire rack to cool completely. Store in an airtight container.
Notes
*All the dry ingredients are to be scooped and leveled (rather than pour from the pouch and level).
**If desired, reduce the vanilla to 1 tsp and add seeds of 1 small vanilla bean when blending butter and sugars.
***I used 2/3 cup of each bittersweet, semi-sweet and milk chocolate chips because the blend of the three is my favorite, but use whatever kind you prefer.