Line a jelly-roll pan with foil; coat foil with cooking spray. Place chicken on prepared pan; sprinkle with pepper. Lightly coat chicken with cooking spray. Bake, uncovered, at 450° for 7 minutes or until lightly browned.
Combine hot sauce and next 3 ingredients (through garlic) in an oval 4-quart electric slow cooker coated with cooking spray.
Remove chicken from pan; drain on paper towels. Place chicken in slow cooker, tossing gently to coat with sauce. Cover and cook on HIGH for 3 hours or until chicken is very tender. Serve with Blue Cheese Dip, carrot sticks, and celery sticks.