1) In a medium-sized bowl, combine the flour, cocoa, baking soda, baking powder, salt, cinnamon, ginger, cloves, and xanthan gum.
2) In a separate bowl, beat the butter and sugar until light and fluffy. Add the egg and molasses, scraping the bowl between and after additions.
3) Add the dry mixture and mix until just combined. Cover and refrigerate dough for an hour at least, or overnight for optimum results.
4) Preheat the oven to 350°F and line baking sheets with parchment.
5) Scoop tablespoon-sized amounts of dough and roll in sparkling or granulated sugar if desired.
6) Bake for 8 to 11 minutes, or until just set.
Yield: 20 to 24 cookies.