Preheat oven to 325ºF (160ºC). Place ribs meat-side up in a single layer in a roasting pan or casserole dish. In a small bowl, combine chili powder, brown sugar, cumin, salt and pepper; sprinkle over ribs and rub into meat. Pour beer into pan. Cover pan with foil; bake until ribs are tender, about 2 hours.
Preheat lightly oiled barbecue to medium-high. Brush ribs with 1/2 cup (125 mL) of the barbecue sauce. Place ribs on grill; close lid and grill until ribs start to char, 3 to 4 min. per side. Brush with remaining barbecue sauce before serving.
This is the perfect recipe to prepare ahead: Bake the ribs up to 48 hours in advance; let cool, cover and refrigerate. Ribs can be barbecued just before serving.