Preheat your oven to 300°F.
Pat the baby back ribs dry with paper towels. Trim any excess fat if desired.
In a small bowl, combine the brown sugar, smoked paprika, garlic powder, onion powder, chili powder, salt, and black pepper.
Rub the spice mixture evenly over both sides of the ribs, ensuring a good coating.
Place the seasoned ribs on a baking sheet lined with foil or in a shallow roasting pan. Cover tightly with another layer of foil to lock in steam.
Bake in the preheated oven for 2.5 to 3 hours, or until the ribs are tender and the meat easily pulls away from the bone.
Optional: For a crispier finish, uncover the ribs, increase the oven temperature to 400°F, and bake uncovered for an additional 10 minutes.
Remove from the oven, let rest for a few minutes, then slice and serve.