Slow-Cooked Stuffed Peppers

Cut and discard tops from peppers; remove seeds. In a large bowl, mix beans, cheese, salsa, onion, corn, rice, chili powder and cumin; spoon into peppers. Place in a 5-qt. slow cooker coated with cooking spray., Cook, covered, on low until peppers are tender and filling is heated through, 3-4 hours . If desired, serve with sour cream.