Remove the membrane from the back of the ribs if still attached.
In a small bowl, mix salt, black pepper, paprika, garlic powder, and onion powder.
Rub the seasoning evenly over both sides of the ribs.
Cut ribs into sections if needed and place them inside the crockpot.
Pour barbecue sauce over the ribs, coating them well.
Cover and cook on LOW for 7–8 hours or HIGH for 4–5 hours, until ribs are very tender.
Optional: Transfer ribs to a baking sheet, brush with extra BBQ sauce, and broil for 3–5 minutes to caramelize the surface.
Serve hot with additional barbecue sauce if desired.