Place the chicken breasts in a plastic bag or wrap them in plastic wrap and pound them until the breast is a uniform ¼-½” thick.
Add the flour to a shallow bowl, the beaten egg to another shallow bowl, and the breadcrumbs to a third bowl.
Dip the chicken breasts one at a time into the flour, followed by the eggs, and breadcrumbs.
Spray the air fryer basket with olive oil spray and add the breaded chicken, making sure not to overcrowd the basket.
Cook the chicken breasts at 375°F for 10 minutes.
Flip the chicken and top with marinara (about 2 tablespoons each), followed by one ounce of mozzarella each.
Cook for an additional 4 minutes at 375°F, or until the cheese has melted. Serve immediately, garnished with fresh basil, if desired.
Notes
Storage: Store any leftovers in an airtight container in the fridge for up to 4 days. They can be reheated in the air fryer at 375°F for 4 minutes to get it nice and crispy again.