how to make ribs tender in the oven
Preheat oven to 250 degrees F (120 degrees C). Mix ancho chile powder, white sugar, brown sugar, salt, black pepper, cumin, dry mustard, cayenne pepper, and chipotle pepper in a small bowl until combined. Place ribs meat-side down on aluminum foil. Prick back of rib rack several times with a knife. Generously apply coating of dry rub to all sides of rib rack. With rib rack meat-side down, fold foil around it to create a tight seal. Transfer to sheet pan. Bake in preheated oven until tender and cooked through, about 2 hours.