Preheat your grill to 300°F (150°C).
Remove the membrane from the back of the ribs.
Mix brown sugar, paprika, garlic powder, onion powder, black pepper, salt, and cayenne pepper.
Rub the spice mixture over both sides of the ribs.
Place the ribs on the grill, bone side down, and cook for 1.5 hours.
Baste the ribs with barbecue sauce every 30 minutes.
Check for tenderness; the meat should pull back from the bones.
Move the ribs to direct heat for the last 10 minutes for caramelization.
Remove from the grill and let rest for 10 minutes.
Slice, serve, and enjoy!