Step 1: Prepare the Ribs. Pat the ribs dry with paper towels. On the underside of each rack, locate the thin membrane (silverskin). Use a knife to lift a corner of the membrane, then grip it with a paper towel and peel it away completely. Trim any excess fat if desired.
Step 2: Make the Dry Rub. In a small bowl, combine the brown sugar, smoked paprika, garlic powder, onion powder, salt, black pepper, cayenne pepper (if using), and 2 tablespoons of apple cider vinegar. Mix well until it forms a thick paste.
Step 3: Apply the Rub and Marinate. Generously apply the dry rub paste all over both sides of the rib racks, massaging it into the meat. Wrap each rack tightly in plastic wrap and refrigerate for at least 2 hours, or ideally, overnight (8-12 hours) for best flavor penetration and tenderness.
Step 4: Slow Roast. Preheat your oven to 275°F (135°C). Place the rubbed ribs, meat-side up, on a large baking sheet lined with heavy-duty aluminum foil. You can also place them on a wire rack set inside the baking sheet. Cover the ribs tightly with another layer of aluminum foil, sealing the edges to create a steamy environment.
Step 5: Bake Until Tender. Bake for 2.5 to 3.5 hours, or until the ribs are very tender and the meat easily pulls away from the bone when gently probed with a fork. The exact time will depend on the thickness of your ribs.
Step 6: Prepare the BBQ Glaze. While the ribs are baking, combine your favorite BBQ sauce, honey, and an additional splash (about 1 tablespoon) of apple cider vinegar in a small saucepan. Simmer over low heat for 5-7 minutes, stirring occasionally, until slightly thickened. Set aside.
Step 7: Glaze and Caramelize. Once the ribs are tender, remove them from the oven. Carefully unwrap them and discard any accumulated liquid in the foil. Increase the oven temperature to 400°F (200°C) or switch to the broiler setting (monitor closely if broiling). Brush a generous layer of the prepared BBQ glaze over the ribs.
Step 8: Finish Baking. Return the glazed ribs to the oven (uncovered) and bake or broil for 10-15 minutes, or until the glaze is caramelized, slightly sticky, and bubbling. Watch carefully to prevent burning. Remove from oven, let rest for 5-10 minutes, then slice and serve hot with extra BBQ sauce if desired.