Remove the membrane on the back of the ribs. Start by loosening part of it with a knife at one corner, then grab it with your hand and pull it off. If the membrane is slippery, use a paper towel to help grip it. Removing the membrane helps the spices penetrate the meat from the rib side and keeps the meat tender — the membrane can be quite tough when cooked.
Place the ribs in a plastic bag and add the dry rub — approximately 1/2 cup for country ribs (3/4 cup for full racks). Let stand one to three hours at room temperature. Or, for stronger flavor, let it sit in the refrigerator for up to one day.
Heat the oven to 275°F. Place the ribs meaty side down, wrapped in aluminum foil, on a rack on a rimmed baking sheet. Roast for 2 hours.
Open up the aluminum foil and turn the ribs meaty side up. Brush with your favorite barbecue sauce and cook for another hour, or until the bones have separated from the meat.
Remove the ribs from the oven, turn them meaty side down and wrap completely in foil to seal. Let the foil-wrapped ribs rest at room temperature for 15–30 minutes. Unwrap, cut between the bones, and serve with the remaining barbecue sauce on the side.