Preheat oven to 350 degrees and grease a glass baking dish
Add bread crumbs, Italian seasoning, garlic powder, and Parmesan cheese together on a plate and then egg whites on a separate plate
Take a piece of chicken and dip in egg whites both sides and then in bread crumb mixture and then repeat again with egg whites and bread crumbs.
Do the same with the other chicken piece and put both in glass baking dish and cook for 20-30 minutes depending on thickness of chicken breast.
After cooking take dish out and put spaghetti sauce and then the mozzarella cheese on top of both pieces of chicken and put back in oven for 5 minutes or until cheese is melted
Notes
The Right Chicken: Get thin-cut chicken breasts. They cook evenly and are quicker to bake.
Cheese Matters: Freshly grated Parmesan beats the pre-grated stuff, hands down. The taste difference is like night and day.
Breadcrumbs: If you've got stale bread lying around, pulse it in a food processor to make your own breadcrumbs. They'll taste much better than store-bought.
Sauce: If you can, go for homemade spaghetti sauce. If not, try to find a jar with the least amount of additives. Your taste buds will thank you.
Oven Watch: Keep an eye on the chicken when it's under the broiler. It can go from golden to burnt in a heartbeat.
Leftovers: If you're lucky enough to have leftovers, reheat them in the oven instead of the microwave. The crust stays crispy that way.