Preheat oven to 425 degrees. Butter a baking dish. In a bowl, combine mayonnaise and Parmesan cheese. Pour breadcrumbs into a shallow pie plate or dish.
Wipe chicken breast halves dry with a paper towel. Using a small rubber spatula or a food brush, coat chicken breast halves with mayonnaise mixture, then roll in breadcrumbs, pressing lightly to help crumbs stick.
Bake in a preheated oven for 20 minutes or until thoroughly cooked. Makes 4 servings. Enjoy!