In large resealable food-storage plastic bag, mix buttermilk, dressing mix and chicken. Seal bag; turn bag several times to coat chicken. Refrigerate at least 1 hour or overnight.
Heat oven to 425°F. Spray 15x10x1-inch pan with cooking spray. In shallow dish, mix breading ingredients. Remove chicken pieces one at a time from buttermilk mixture. Dip chicken in breading, turning to coat completely; shake off excess. Place chicken, bone side down, in pan. Lightly spray top of chicken with cooking spray.
Bake 35 to 40 minutes or until juice of chicken is clear when thickest piece is cut to bone (170°F for breasts; 180°F for thighs and legs).