Preheat oven to 350°F.
Cut top and bottom off of onions, and then slice into 1/2 inch rings, keeping two rings together to make onion rings thick and sturdy enough to wrap.
Wrap one slice of bacon tightly around onion, taking care not to overlap too much. Use a second piece if need be. Use a toothpick to hold in place.
Coat the wrapped onion rings in brown sugar rub, and place on wire baking rack set on a sheet pan.
Cook for 15 minutes, or until bacon is crispy. Once crispy, carefully brush onion rings with hot bbq sauce and cook for additional 5 minutes or until sauce sets. Optional: Serve with bbq ranch dipping sauce by combining 1/2 Cup ranch with 1/2 Cup BBQ sauce.