Preheat your smoker to 225°F (107°C).
In a small bowl, combine brown sugar, paprika, garlic powder, onion powder, black pepper, and salt.
Rub the spice mixture all over the brisket, covering it completely.
Place the brisket in the preheated smoker.
Smoke the brisket for 6-8 hours or until it reaches an internal temperature of 195°F (90°C).
During the last hour of smoking, brush the brisket with barbecue sauce.
Once done, remove the brisket from the smoker and let it rest for at least 30 minutes before slicing.
Slice against the grain and serve with additional barbecue sauce if desired.