Line cookie sheets with parchment paper or silicone mats and set aside.
In a medium bowl combine flour, cocoa powder, xanthan gum, baking soda, and salt. Mix well.
In a large bowl or electric stand mixing bowl cream butter and sugars well.
Next mix in eggs one at a time; then add in vanilla and peppermint extracts.
Slowly add in the flour mixture until just combined.
Allow dough to rest in the refrigerator for 20-30 minutes; otherwise it's very sticky to handle.
Preheat oven to 350°F. Remove dough from the refrigerator.
Scoop dough out by a rounded tablespoon and roll into a ball. Place onto covered cookie sheet. Space cookie balls about 2 inches apart. 12 balls will be the perfect fit on a standard size cookie sheet.
After the cookie sheet is full slightly flatten each cookie and place in the oven.
Bake cookies 1 sheet at a time for 8 minutes. Set a timer for these. Cookies will look under baked, but will finish baking on the cookie sheet when cooling. After cookies have cooled 3-4 minutes, transfer them to a wire rack.
After cookies have cooled another 15-20 minutes, melt dairy free white chocolate either in a microwave or over the stove top. Prepare parchment paper for the next step.
Dip half of cookie into the white melted chocolate, then place on parchment paper to set. Sprinkle crushed candy cane pieces over melted chocolate cookie. Allow to set about 10 minutes before serving. Cookie can also be baked a day or two in advance of dipping them in white morsels.
Cookies must be stored in an airtight container for up to a few days.