1. Preheat your smoker to 225°F (110°C).
2. In a bowl, mix together brown sugar, paprika, black pepper, salt, chili powder, garlic powder, onion powder, and cayenne pepper.
3. Remove the membrane from the back of the ribs and apply the spice rub evenly on both sides.
4. Place the ribs in the smoker and cook for 3 hours.
5. After 3 hours, wrap the ribs in aluminum foil and cook for another 2 hours.
6. Remove the foil and cook for an additional hour, basting with your favorite BBQ sauce if desired.
7. Remove the ribs from the smoker and let them rest for 10 minutes before serving.