Heat oven to 400°F. Spray 15x10x1-inch baking pan with nonstick cooking spray.
In shallow bowl, combine buttermilk, salt and ground red pepper; mix well. Place corn flake crumbs in another shallow bowl. Dip chicken in buttermilk mixture; coat with crumbs. Place crumb-coated chicken breast halves in corners of sprayed pan.
In large bowl, combine potatoes, bell pepper and onion. Sprinkle with cheese, garlic powder and paprika; toss to coat evenly. Place in center of baking pan. Drizzle butter over chicken and vegetables.
Bake at 400°F. for 30 to 40 minutes or until chicken is fork-tender, its juices run clear and potatoes are tender, stirring vegetables once halfway through baking.