In a large mixing bowl, thoroughly mix the sugar cookie dough and cocoa powder using a hand mixer or stand mixer.

Cover the dough with plastic wrap and chill in the refrigerator for about one hour.

Preheat the oven to 350°F (175°C).

Use a cookie scoop to form even balls of dough. Roll the balls in your hands to create a smooth shape.

Roll each cookie dough ball in a shallow bowl filled with coarse sugar until completely coated.

Place the balls 1½ inches apart on a parchment-lined cookie sheet. Slightly flatten the tops with your palm.

Bake for 8 to 9 minutes until cookies are puffy and the dough no longer looks wet.

Remove from the oven and gently press a chocolate kiss into each warm cookie. Allow to cool for a couple of minutes before transferring to a cooling rack.