Heat oven to 400°F. Spray 17x12-inch half-sheet pan with cooking spray.
In medium bowl, mix all ingredients except dressing. Shape mixture into 24 (1 1/2-inch) balls; place in pan.
Bake 17 to 20 minutes or until meat thermometer inserted in center of meatballs reads at least 165°F. Serve warm with blue cheese dressing.