Preheat your oven to 300°F (150°C).
In a small bowl, mix together the brown sugar, paprika, salt, black pepper, garlic powder, and onion powder.
Rub the spice mixture all over the ribs.
Wrap the ribs tightly in aluminum foil and place them on a baking sheet.
Bake in the preheated oven for 2.5 to 3 hours, or until the ribs are tender.
Remove the ribs from the oven and carefully unwrap them.
Brush the ribs with BBQ sauce and place them back in the oven, uncovered, for an additional 30 minutes.
Remove from the oven and let rest for a few minutes before serving.