Prepare the chicken: Place each chicken breast between two sheets of plastic wrap. Pound them to an even 1/2-inch thickness using a meat mallet or rolling pin.
Set up your breading station: Place flour in one shallow dish. In a second dish, whisk the egg and water together. In a third dish, combine the panko breadcrumbs, 1/4 cup Parmesan cheese, Italian seasoning, garlic powder, salt, and pepper.
Dredge the chicken: Coat each piece of chicken first in the flour, shaking off excess. Dip it into the egg mixture, letting excess drip off. Finally, press the chicken firmly into the breadcrumb mixture to coat both sides completely.
Preheat the air fryer to 380°F (195°C) for 5 minutes. Lightly spray the air fryer basket with cooking spray.
Cook the chicken: Place the breaded chicken breasts in a single layer in the air fryer basket, ensuring they do not overlap. Spray the tops lightly with cooking spray.
Air fry for 10 minutes. Flip the chicken breasts, spray the second side lightly, and cook for another 5 to 8 minutes, or until the internal temperature reaches 165°F (74°C).
Assemble the parmesan: Remove the cooked chicken from the air fryer. Spoon about 2 tablespoons of marinara sauce over the top of each breast. Sprinkle with mozzarella cheese and the remaining 2 tablespoons of Parmesan cheese.
Return the chicken to the air fryer and cook at 380°F (195°C) for 2 to 3 minutes, or until the cheese is melted and bubbly.
Serve immediately over your favorite pasta or with a side salad.
Notes
For extra crispy results, let the breaded chicken rest in the refrigerator for 15 minutes before air frying.
Use panko breadcrumbs for the best texture in the air fryer.
If your air fryer cooks unevenly, you may need to flip the chicken halfway through the initial cooking time.