Remove the silver skin membrane from the back of the ribs. Place them in a shallow baking dish and pour 2 cups of the Dr. Pepper over the ribs. Cover with plastic wrap and refrigerate overnight.

In a blender or food processor, mix the remaining soda, ketchup, brown sugar, cider vinegar, liquid smoke, Worcestershire sauce, salt and pepper. Blend until smooth. Reserve half for later.

Preheat the oven to 225°F. Cover a large baking sheet with tin foil large enough to envelop the ribs.

Remove the ribs from the marinade and place them on the baking sheet. Brush the ribs all over with half the sauce. Pull the foil around the ribs and create a sealed packet.

Roast for 2 1/2 hours or until very tender. They should reach 200°F and fall apart easily with a fork.

Remove the ribs from the oven and discard the foil packet. Place the ribs on the baking sheet and baste with the reserved sauce. Turn the oven on broil and make sure a rack is near the top of the oven. Broil for about 10 minutes, until the top is bubbly and a little charred.