In the bowl of your stand mixer fitted with the paddle attachment, beat the sugar and oil together on medium-high speed until well combined, about 2 minutes.
Scrape down the sides and bottom of the bowl. Add the eggs one at a time, beating after each addition.
Add and beat in the vanilla and peppermint extracts. Scrape down the sides and bottom of the bowl.
In a separate medium-sized bowl, stir together the flour, cocoa mix, baking powder, and salt. With your stand mixer on low speed, gradually add the dry ingredients to the wet ingredients, beating until everything is just combined. The dough will be slightly tacky.
Cover your mixing bowl with plastic wrap and place it in your refrigerator. Let the cookie dough chill for at least 4 hours or up to overnight.
Wrap presents, decorate the tree, enjoy a glass of eggnog, and/or watch your favorite Christmas movie.
Preheat your oven to 350° F.
Line your baking sheets with parchment paper. Add the powdered sugar to a small bowl.
Working with about one tablespoon of dough at a time, roll it into a ball. Place the dough ball in the powdered sugar and turn to coat it completely on all sides.
Place the coated dough ball on one of your prepared baking sheets. Continue until all the dough has been used up, placing the dough balls about 1 1/2 inches apart on your baking sheets.
Transfer the baking sheets to your oven and bake the cookies for 10 minutes. Remove the baking sheets and let the cookies rest for 5 minutes before transferring them to a wire rack to finish cooling.
This recipe makes about two dozen cookies. However, it can easily be doubled if necessary. The cookies will stay soft and fresh for 3 to 5 days when stored in an airtight container at room temperature.