Preheat oven to 350℉ (180℃)
Prepare 2 baking sheet pans by lining with parchment paper or silicone baking mats.
In a medium bowl, whisk together flour, cocoa powder, baking soda and salt. Set aside for later.
1⅔ Cups Gluten-free flour, ¼ Cup Cocoa powder, 1½ teaspoon Baking soda, ½ teaspoon Salt
Using a stand mixer with the paddle attachment, begin mixing the butter, granulated sugar and brown sugar together until light and creamy (2 - 3 minutes on medium speed). Scrape down sides of bowl as needed. Note - a hand mixer may also be used.
1 Cup Unsalted butter, ¾ Cup Granulated sugar, ¾ Cup Brown sugar
Add the egg to mixing bowl. Mix on medium speed until combined, scraping down sides of bowl as needed.
1 Large Egg
Add flour mixture to mixing bowl. Mix on medium speed until combined, scraping down sides of bowl as needed.
Add chocolate chips to mixing bowl and stir briefly until chips are evenly distributed.
1 Cup Bittersweet chocolate chips
Scoop approximately 1½ tablespoons of cookie dough and roll into a ball. Gently roll each ball of dough in sugar, coating it lightly on all sides.
1 Cup Granulated sugar
Place balls of cookie dough on prepared baking sheets. Gently press down on each cookie to flatten slightly. Leave at least 2" of space between each cookie to allow for spreading.
Bake cookies for 13 - 14 minutes. Edges will be slightly browned, top will look crackled and center of cookie will have risen slightly.
Allow cookies to cool on baking sheets for 10 minutes, then transfer to a wire rack to cool completely.