01 -
Line two cookie sheets with parchment paper and set aside without preheating the oven.
02 -
In a large mixing bowl, whisk together the sugar cookie mix and cocoa powder until combined.
03 -
Using a hand or stand mixer, beat in the butter and egg until a thick dough forms.
04 -
Scoop out a large ball of dough using a 1 ½ tablespoon cookie scoop, flatten into a disc, and place two unwrapped Rolos at its center. Gently form the dough into a smooth ball.
05 -
Roll each formed ball in sanding sugar or powdered sugar if desired, then place it on the prepared cookie sheet.
06 -
Cover the cookie sheets with plastic wrap and refrigerate for at least 30 minutes.
07 -
Preheat the oven to 350°F (180°C) several minutes before baking.
08 -
Remove the cookie sheets from the refrigerator and discard the plastic wrap. Bake the cookies for 10-15 minutes, or until the edges are set, and the tops begin to crack.
09 -
Remove cookies from the oven and let cool for at least 5 minutes before transferring to a cooling rack or serving warm.