Preheat your oven to 275°F (135°C).
In a bowl, mix salt, brown sugar, paprika, black pepper, garlic powder, onion powder, cumin, and cayenne pepper.
Rub the spice mixture all over the pork ribs evenly.
Place the ribs on a baking sheet lined with aluminum foil and cover with another piece of foil.
Bake for about 3 to 4 hours, or until the meat is tender and falls off the bone.
Remove the ribs from the oven and discard the top foil. Brush the barbecue sauce over the ribs.
Increase the oven temperature to 350°F (175°C) and return the ribs to the oven, uncovered, for an additional 10 minutes, or until the sauce is caramelized.
Let the ribs rest for a few minutes before serving.