Step 1

For the ribs: Preheat the oven to 350 degrees F. Line a large rimmed baking pan with foil.

Step 2

Place the ribs on the prepared baking pan meat-side up. Sprinkle them with the paprika, garlic powder, 1 tablespoon salt and a generous amount of pepper. Rub the spices all over the ribs.

Step 3

Cover the pan tightly with foil and bake until the meat is very tender and can easily be pulled off the bone, about 2 hours.

Step 4

For the barbecue sauce: Meanwhile, heat the oil in a medium saucepan over medium heat. Add the onions and 1/2 teaspoon salt and cook, stirring often, until very soft and golden brown, about 20 minutes. Add the garlic and cook, stirring, 1 minute. Add the ketchup, orange juice, Worcestershire, chipotles and adobo and 1/2 cup water. Increase the heat to bring to a boil, then reduce the heat to keep at a simmer until slightly thickened, about 10 minutes. Transfer to a blender and puree until smooth (be careful when blending hot liquids). Alternately, an immersion blender can be used in the pot.

Step 5

Finish the ribs: Preheat the grill to medium-high (or set the oven to broil).

Step 6

Reserve about a cup of the barbecue sauce for serving alongside the ribs. Brush a small amount of the remaining sauce on the bone side of the ribs and a generous amount on the meaty side.

Step 7

Grill the ribs, meaty-side up, until the underside is lightly charred, about 3 minutes. Turn the ribs over and grill until the meaty side is charred in spots, 3 to 5 minutes (if using the oven, simply broil for 3 to 5 minutes). Transfer to a cutting board and cut each rack in half. Serve immediately with the reserved sauce on the side.