Preheat your oven to 275 degrees Fahrenheit (135 degrees Celsius). Set out a large roasting pan or rimmed baking sheet and a generous sheet of aluminum foil.

Flip the ribs meat-side down. Slide a knife gently under the thin membrane on the back of the rack and peel it away using your fingers. Use a kitchen towel for grip if it is slippery. Removing this membrane is essential for tender results.

Season both sides of the ribs generously with salt and black pepper.

Place the ribs meatiest-side down in your roasting pan. Cover tightly with aluminum foil, pressing the edges firmly to create a good seal. If your foil is too narrow, wrap each rack individually in its own foil packet and place on the baking sheet.

Bake for 2 and a half to 3 and a half hours. Check at the 2-hour mark. The ribs are ready when a sharp knife pierces the meat with little to no resistance. If still tough, increase oven temperature to 300 degrees Fahrenheit and continue baking.

While the ribs bake, make the BBQ sauce. Heat the olive oil in a small saucepan over medium heat. Add the diced onion and cook for 5 to 8 minutes, stirring occasionally, until completely soft and translucent.

Stir in the ground cumin and cook for 30 seconds. Add the ketchup, hot chili sauce, brown sugar, and apple cider vinegar. Stir to combine, season with salt, and simmer for 2 minutes. Set aside.

Remove the ribs from the oven and carefully discard the foil. Generously brush the BBQ sauce over both sides of the rack.

Move an oven rack near the top and set the broiler to high. Broil the ribs for 3 to 4 minutes, watching closely, until the sauce caramelizes and bubbles into a glossy glaze. Serve immediately.