Ingredients:
- 2 racks St. Louis spare ribs, (2 1/3 to 3 pounds each), cut into 3- or 4-rib sections
- 1/4 cup dark brown sugar, packed
- 2 tablespoons chili powder
- 1 tablespoon salt
- 2 teaspoons onion powder
- 1 teaspoon allspice
- 1 1/2 cup (12-oz) can root beer, (not diet), divided
- 2 tablespoons cornstarch, dissolved in 2 tablespoons cold water