1Heat oven to 375°F. Spray cookie sheet with cooking spray.
2In shallow dish or pie plate, mix bread crumbs and dressing mix. In another shallow dish or pie plate, place sour cream.
3Dip each chicken breast in sour cream, coating well, then roll in bread crumb mixture; place on cookie sheet. If desired, spray chicken with cooking spray. Discard any remaining bread crumb mixture and sour cream.
4Bake 30 to 35 minutes or until juice of chicken is clear when center of thickest part is cut (170°F).