How to Make It
Preheat oven to 275°F. Stir together brown sugar, salt, paprika, black pepper, onion powder, garlic powder, and cayenne in a small bowl. Rub 3 tablespoons of spice blend all over ribs, reserving remaining spice blend. Place ribs in a piece of heavy-duty aluminum foil; pour cola over ribs. Fold edges of foil together, and seal. Place ribs on rimmed baking sheet; bake in preheated oven 2 hours and 30 minutes.
Combine ketchup, water, molasses, vinegar, mustard, liquid smoke, and reserved spice blend in a small saucepan over medium-high. Bring to a boil, stirring constantly. Reduce heat to medium-low; cover and simmer 10 minutes. Remove from heat.
Remove ribs from oven. Adjust oven to broil. Line a rimmed baking sheet with aluminum foil. Carefully unwrap cooked ribs, and transfer ribs, bone side up, to prepared baking sheet; discard foil package. Brush ribs with sauce, and broil 2 minutes. Flip ribs, and brush with more sauce. Broil until bubbly, about 2 minutes. Serve with remaining sauce.