01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together the gluten-free flour, baking soda, and salt until evenly distributed.
03 - In a large mixing bowl, beat the softened butter, brown sugar, and granulated sugar using an electric mixer until light and creamy, about 2 minutes.
04 - Add the egg and vanilla extract to the butter mixture, beating until well combined and smooth.
05 - Gradually add the dry ingredients to the wet mixture, mixing on low speed until just combined. Avoid overmixing.
06 - Gently fold in the chopped pistachios and half of the dark chocolate chips until evenly distributed throughout the dough.
07 - Scoop tablespoon-sized balls of dough onto the prepared baking sheets, spacing them about 2 inches apart to allow for spreading.
08 - Press a few of the remaining chocolate chips onto the top of each cookie dough ball for a bakery-style appearance.
09 - Bake for 10 to 12 minutes, or until the edges are golden and the centers are just set. Do not overbake.
10 - Let the cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.