Preheat your oven to 300°F (150°C).
Remove the thin membrane from the back of the ribs.
In a small bowl, mix together brown sugar, paprika, salt, black pepper, garlic powder, onion powder, and cayenne pepper.
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 hours.
Remove the ribs from the oven and carefully unwrap the foil.
Brush the ribs with BBQ sauce.
Place the ribs back in the oven, uncovered, and bake for an additional 10-15 minutes, or until the sauce is caramelized.
Let the ribs rest for a few minutes before serving.