Prepare the Ribs:

Preheat your oven to 275°F (135°C).

Remove the membrane from the back of the ribs. Slide a knife under the membrane at one end of the ribs and use a paper towel to grip and pull it off.

Make the Dry Rub:

In a small bowl, mix together the brown sugar, smoked paprika, garlic powder, onion powder, black pepper, salt, chili powder, cumin, mustard powder, and cayenne pepper (if using).

Season the Ribs:

Rub the olive oil over both sides of the ribs.

Generously sprinkle the dry rub over both sides of the ribs, pressing it into the meat with your fingers.

Wrap and Cook:

Place each rack of ribs on a large piece of aluminum foil, meat side up. Wrap the ribs tightly in the foil, ensuring they are completely sealed.

Place the wrapped ribs on a baking sheet and bake in the preheated oven for 2.5 to 3 hours, or until the ribs are tender and the meat is pulling away from the bones.

Finish with Barbecue Sauce:

Carefully remove the ribs from the oven and unwrap them.

Preheat your broiler.

Brush the ribs generously with barbecue sauce on both sides.

Place the ribs under the broiler for about 5-7 minutes, or until the sauce is caramelized and bubbly. Watch closely to prevent burning.

Serve:

Remove the ribs from the oven and let them rest for a few minutes before cutting into individual ribs.

Serve with additional barbecue sauce on the side, if desired.