Preheat your oven to 275°F (135°C). Remove the membrane from the back of the rack of Baby Back Pork Ribs and pat the ribs dry with paper towels.
Spread a thin layer of Yellow Mustard over both sides of the ribs to help the rub adhere. In a bowl, combine Light Brown Sugar, Paprika, Kosher Salt, Ground Black Pepper, Garlic Powder, Onion Powder, Chili Powder, Cayenne Pepper and Dry Mustard; mix until evenly blended.
Generously rub the spice mixture all over the ribs, coating both sides. Lay the ribs meat-side up on a large piece of heavy-duty foil.
Pour about 1/2 to 3/4 cup of Apple Juice onto the foil around (not directly drenching) the ribs to create steam during baking, then tightly seal the foil into a packet.
Place the wrapped ribs on a baking sheet and bake in the preheated oven for 2 1/2 to 3 hours, or until the meat is very tender and pulling away from the bone.
While the ribs bake, make the barbecue sauce by whisking together Ketchup, a few tablespoons of Light Brown Sugar, Apple Cider Vinegar, Molasses, Worcestershire Sauce, a little extra Yellow Mustard if you like tang, a pinch of Smoked Paprika, and salt and pepper to taste. Adjust sweetness or acidity to your preference.
When the ribs are tender, carefully open the foil (watch for hot steam) and transfer the ribs to a foil-lined baking sheet meat-side up. Brush a generous layer of the barbecue sauce over the ribs.
Finish the ribs under a hot broiler or on a preheated grill for 5–10 minutes, watching closely, until the sauce caramelizes and develops a few charred spots—brush with more sauce and repeat if you want a thicker glaze.
Remove the ribs from the heat and let them rest for 5–10 minutes. Slice between the bones, serve with extra sauce on the side, and enjoy.
