Preheat your oven to 325°F. Line rimmed baking sheets with unbleached parchment paper and set them aside.

In a large bowl, place the flour, xanthan gum, cocoa powder, baking powder, baking soda, salt and granulated sugar, and whisk to combine well. Create a well in the center of the dry ingredients and add the butter, eggs and vanilla, mixing to combine after each addition. The dough will be soft. Add the optional red food coloring and mix until the cookie dough is a uniform red-tinged color. Divide the dough into 24 equal portions, each about 1 1/2 tablespoons, and place on the prepared baking sheets about 1 1/2-inches apart. The dough will be sticky, so use either an ice cream scoop or two spoons. Place the dough in the freezer until firm (5 to 10 minutes). Place the confectioners’ sugar in a small bowl and set it aside.

Remove the cookie dough from the freezer and roll each portion tightly into a ball. Working quickly, drop each ball of dough into the bowl of confectioners’ sugar and roll it around to coat on all sides. Press the ball into a disk about 1/2-inch thick, place in the confectioners’ sugar to coat again completely and return it to the baking sheet.

Place the baking sheets, one at a time, in the center of the preheated oven. Bake until the cookies are puffed and set in the center (about 14 minutes). Remove from the oven and allow to cool completely on the baking sheet.