Prep: Preheat oven to 400°F. Cover a rimmed baking sheet with parchment paper or foil that’s been sprayed with cooking spray.
Set Up Breading Stations: In a shallow dish, combine bread crumbs, Parmesan cheese, Italian seasoning, garlic powder, 1/4 teaspoon salt, and a pinch of pepper. In a second shallow dish, whisk together the egg and a splash of water.
Slice Chicken Cutlets: On a cutting board, slice chicken in half lengthwise, resulting in 6 thinner chicken breasts (see article for pictures). Season the front and back of each chicken breast with a pinch of salt and pepper.
Bread Cutlets: Dip chicken breasts, one at a time, in egg mixture, turning to coat. Allow excess to drip off. Then dip chicken pieces in breadcrumb mixture, turning to coat. Press the mixture onto the chicken so it sticks. Place breaded chicken on the sheet pan. (Freezing instructions begin here.)
Bake: Bake for 15-18 minutes, until the thickest piece registers close to 160°F internally with a meat thermometer.
Add Topping: Top each chicken breast with about 1/4 cup of marinara sauce (enough to mostly cover the piece). Then, sprinkle about 1/4 cup of shredded mozzarella cheese over the top of each piece (or 1-2 slices of fresh mozzarella), as well. Put chicken back in the oven for 5 minutes or until the cheese is melted.
Serve: Serve warm over pasta, if desired.
Freeze For Later: Follow Steps 2-4. Place in single layers in a freezer container or flat gallon-sized bag. Divide layers with parchment paper. Seal tightly and freeze. Freeze alongside a bag of shredded mozzarella cheese.
Prepare From Frozen: Thaw chicken completely in the refrigerator over night. Preheat the oven to 400°F. Follow Steps 5-7.