Preheat your grill or oven to about 300 F.
Combine the white sugar, paprika, brown sugar, salt, onion powder, garlic powder, cayenne, and black pepper in a small mixing bowl. Set aside.
Prepare the ribs by removing the membrane and trimming excess fat. Lay the ribs on a sheet of foil.
Liberally coat the ribs with the rub, then seal tightly in foil, using multiple sheets as needed to ensure there won't be leaks.
If grilling, place meat over indirect heat. Cook with the meaty-side up and cook for about 1 1/2 hours, or until the meat is fall-off-the-bone tender.
Remove foil and begin glazing with the BBQ sauce. Liberally brush one side with the sauce, then cook about 7-10 minutes. Flip and baste the other. Repeat until each side has been glazed twice.
Serve warm and with plenty of napkins!