Combine chicken and 2/3 cup buttermilk in plastic bag. Refrigerate 2 hours or overnight.
Drain chicken in colander; discard buttermilk. Lightly coat baking sheet with cooking spray.
Heat oven to 350 degrees F.
Beat together remaining buttermilk, egg, mustard, salt and pepper in small bowl. Whisk in flour. Combine cornflake crumbs and Parmesan in shallow pan.
Dip chicken pieces in egg mixture, then cornflake crumbs to coat completely. Place chicken on prepared sheet. Mist with light coating of cooking spray.
Bake in 350 degree F oven 20 minutes or until chicken is no longer pink in center and coating is crispy.
Combine flour, sugar, baking soda and salt in bowl. Beat egg yolks in large bowl; stir in buttermilk. Add flour mixture to buttermilk mixture and mix just enough to blend. Stir in butter.
Beat egg whites in bowl until stiff but not dry peaks form. Gently fold whites into batter just to blend.
Make 8 waffles in waffle maker according to manufacturers directions. Stack between sheets of waxed paper on large baking sheet; keep warm in 225 degree F oven.
Combine spreadable fruit and sour cream in small bowl. Makes 8 servings (eight 8-inch waffles).