Preheat the oven to 350°F, line up a baking sheet with parchment paper and set aside.
In a small mixing bowl, mix together the dry ingredients (gluten-free flour, xanthan gum, baking soda, and salt) and set aside.
In a larger mixing bowl, mix together wet ingredients (coconut oil, coconut sugar, egg, plant-based milk, and vanilla extract) until well combined. Add dry ingredients and fold it in.
Chop dark chocolate in smaller pieces and add to the dough. Fold in.
Using 1 ½ tablespoon ice cream scoop, scoop the dough and place the dough balls on a baking sheet lined with parchment paper.
Bake at 350°F for about 12 minutes or until the edges are light brown color and the top is slightly set. Don’t over bake the cookies, otherwise they will come out dry.
When cookies are done, take them out of the oven and let them sit on a baking sheet for about 10 minutes, then transfer to a wire rack to cool off completely.