Form mac and cheese into five to six 1½-oz. balls (approximately the size of a ping pong ball). Place each ball in the center of a 4x4-inch square of plastic wrap. Bring the corners of the plastic wrap to the top and twist together tightly to compact the mac-and-cheese ball. Place wrapped balls in the refrigerator to firm up while the grill is heated.
Prepare grill for two-zone cooking, placing pre-heated charcoal briquets on one half of the grill’s charcoal grate to create a hot and a cool zone. Add 2–3 chunks of your favorite smoking wood to the charcoal, replace the main cooking grate, then adjust the bottom vents to bring the grill temperature to approximately 400°F.
Remove mac-and-cheese balls from the plastic wrap and divide breakfast sausage among the balls. Create a flat disk with the breakfast sausage using clean hands then set a mac-and-cheese ball in the center and begin shaping the sausage around the ball until the mac and cheese is completely covered by a layer of sausage.
Crush the Doritos by hand then place in a food processor or clean coffee grinder and pulse until they are the consistency of breadcrumbs. Place the crumbs into a shallow dish then roll the sausage wrapped mac-and-cheese balls in the nacho cheese crumbs.
Place the balls on the cool side of the grill, cover, and allow them to smoke until they are firm and completely cooked through, approximately 30 minutes.
Remove from the grill and serve.