Preheat the oven to 350 degrees F.
Start by trimming off any fat or tendons from your chicken breasts. Lay your chicken breast in a freezer bag or between two sheets of plastic wrap. Using a meat tenderizer, rolling pin, or the bottom of a mason jar, give the chicken a few good whacks on the thickest part of the chicken breast.
In a small bowl, beat the egg with a fork and add a tablespoon of water. In a separate plate, combine the breadcrumbs, Italian seasoning, garlic powder, and 6 tablespoons of Parmesan cheese.
Dip the raw chicken breast into the egg mixture, roll in the breadcrumb mixture (make sure all areas on the chicken breast are covered), and lay on a parchment paper-lined baking sheet. Season with salt and pepper, then repeat with the rest of the chicken.
Bake in a preheated oven for 30-35 minutes, or until the chicken registers 165 degrees on a digital thermometer in the thickest part.
Remove from the oven and add a thick layer marinara sauce, mozzarella cheese, and the remaining Parmesan cheese over the top. Broil for about 5 minutes, or until the cheese is golden brown.
Take the baked chicken out of the oven and garnish with minced parsley or basil before serving. Enjoy!