Carefully butterfly each chicken breast by slicing horizontally through the center to create four thin cutlets.
Season both sides of the chicken with kosher salt and black pepper.
Place the flour in a shallow bowl and season lightly with salt and pepper.
In a second shallow bowl, beat the eggs until smooth.
In a third bowl, combine the panko breadcrumbs, Parmesan cheese, oregano, red pepper flakes, and garlic powder.
Dredge each chicken piece in the flour, shaking off any excess.
Dip into the beaten eggs, allowing any extra egg to drip off.
Press the chicken into the breadcrumb mixture, coating both sides evenly.
Arrange the breaded chicken in a single layer in the air fryer basket. Cook in batches if necessary.
Air fry at 400°F (200°C) for 5 minutes per side, turning once halfway through cooking.
Spoon marinara sauce over each piece and top with shredded mozzarella.
Return to the air fryer and cook for an additional 3 minutes, or until the cheese is melted and lightly golden.
Serve the Air Fryer Chicken Parmesan immediately, garnished with fresh parsley.