1. Heat broiler. Season chicken with salt and pepper. Slice each breast almost horizontally in half, but leaving one side attached.
2. Arrange a mozzarella slice, tomato slice and basil leaf on bottom half of each breast, keeping filling in center. Fold top of chicken over filling, pressing around edges to seal.
3. Combine bread crumbs and Parmesan on waxed paper. Brush both sides of chicken with mayonnaise. Dip chicken into crumbs; press to adhere.
4. Place chicken on large greased broiling pan. Lightly coat both sides of chicken with cooking spray.
5. Broil 8 inches from heat for 8 to 10 minutes, turning once.