Mix together parmesan cheese, bread crumbs, garlic powder, salt, and pepper to taste.
Dip chicken into beaten egg, then in bread crumb mixture and coat well.
Brown coated chicken on both sides in heated oil. Heat spaghetti sauce.
Place a thin layer of sauce on bottom of casserole dish with part of the sauce, then place browned chicken on the sauce and spoon a little sauce on each chicken breast. Reserve remaining sauce for spaghetti.
Cover and bake in a 325°F oven for 30 minutes.
Remove from oven and top with mozzarella cheese, place back in oven for another 10-15 minutes.