preheat oven to 375F.
Cut chicken breast in half. Flatten each piece with a meat pounder or rolling pin to ensure even cooking. Arrange your chicken pieces in one layer on your baking dish. (If the time permits, add ¾ cup of buttermilk to the chicken and marinate 30 mins to overnight).
In a small bowl, mix the mayonnaise, ½ cup of Parmesan cheese, salt, pepper, and garlic powder. Top each piece of chicken with the mixture and spread evenly.
Sprinkle the ½ cup Parmesan cheese remaining evenly on top
Bake for 45 mins or until cheese is bubbly and golden brown