To make a rub, stir together the salt, black pepper, brown sugar, mustard powder, chipotle powder, allspice, and cayenne. Coat the ribs with the rub on both sides, wrap in plastic, then place in the refrigerator for at least 4 hours.
Heat the oven to 300° F and bring the ribs to room temperature.
In a foil-lined large baking or roasting pan, arrange the ribs with the meat side up, pour in 1/4 cup of Dr Pepper, cover pan tightly with foil and place in the oven.
Meanwhile, to make the glaze, place the Dr Pepper, ketchup, mustard, apple cider vinegar, molasses, and chipotle powder in a pan, bring to a boil and then simmer for 20 minutes until thick and syrupy.
After an hour and a half, take the ribs out of the oven and spread some of the glaze on each side of the racks. Place back in the oven, meat side up and cook uncovered for 30 minutes.
After 30 minutes, take out the ribs and spread more glaze over them and cook for 30 more minutes or until ribs are desired tenderness.
At this point, take the ribs out of the oven, spread more glaze on them and then cook each side under the broiler for four minutes.
Divide and serve!
You can use my chipotle ketchup instead of regular ketchup for the glaze. I used cane sugar Dr Pepper though you can also use regular Dr Pepper, just don’t use diet!