Combine pork rub, brown sugar, and paprika. Dice the belly into one-to-two-inch, square pieces. Generously coat the pork belly. Wrap and refrigerate overnight.
Remove belly from refrigerator and unwrap.
Set smoker with your favorite wood to 275°. Place pieces on rack in smoker and cook for 2 hours.
Transfer pieces after two hours to an aluminum hotel pan cover and cook for two hours more. Uncover pan, drain excess liquid. Toss in BBQ sauce.
Open smoker air vents to raise the temperature and return uncovered pan to smoked cook for 15-20 minutes then remove and rest for 10 minutes before serving.