Preheat the oven to 300°F. Removing the membrane from the back the ribs and cut the rack in half if needed.
If using mustard, coat both sides of the ribs with the yellow mustard.
In a small bowl, mix together the paprika, salt, pepper, garlic powder, onion powder, oregano, and cayenne. Rub the seasoning all over the ribs on both sides.
Place a large piece of aluminum foil down. Add the prepared ribs to the center of the foil. You can also add unseasoned ribs and rub them down with the seasoning directly on the foil. Bring the shorter edges to the center, then fold them over each other to make a seam in the center. Fold in the edges to seal so that you create a packet. Repeat with the other half of the ribs if you cut your rack in half.
Place the ribs on a large baking sheet. Bake 2.5 to 3 hours. The ribs are done when the meat is tender and begins to pull away from the bones.
Carefully remove the ribs from the oven and increase the oven temperature to BROIL. Open the foil packets and spread the BBQ sauce on top of the ribs. Return the ribs to the oven, uncovered, for an additional 3 to 5 minutes or until the sauce is bubbling.
Let the ribs rest for a few minutes before cutting them into individual portions.