1Heat oven to 375°F. To form pocket in each chicken breast, cut 3-inch-long slit in thick side of each breast, cutting into breast about 2 inches and to within 1/2 inch of opposite side.
2In small bowl, mix cheese and ham. Spoon evenly into pockets in chicken; secure openings with toothpicks.
3Place melted butter in shallow dish. Place bread crumbs on large plate. Dip each stuffed chicken breast into butter; roll in bread crumbs to coat. Place in ungreased 13x9-inch (3-quart) glass baking dish. Sprinkle any remaining bread crumbs over chicken.
4Bake 28 to 32 minutes or until juice of chicken is clear when center of thickest part is cut (at least 165°F). Remove toothpicks before serving.