Peel the eggplant and cut into ½-inch thick slices. Place the sliced ​​eggplant on a rack on a baking sheet and generously salt both sides of the eggplant with kosher salt. Let the eggplant sit for at least 30 minutes and up to an hour. Once the eggplant is strained, run the slices under water to rinse off the salt and pat the eggplant dry with a paper towel or clean kitchen towel.
Place 3 shallow dishes in which to prepare the eggplant breading station. In the first dish, mix the flour with ½ teaspoon of salt and garlic powder. In the second bowl, beat the egg with 2 tablespoons of water and a pinch of salt. In the last dish, mix the panko, ⅓ cup Parmesan cheese, the remaining ½ teaspoon garlic powder, a pinch of salt, oregano, and red pepper flakes.
Dip each eggplant slice into the mixture of four, shaking off the excess. Then dip in the egg mixture, letting the excess egg mixture drain off the eggplant. Finally, coat the eggplant slices in the breadcrumb mixture, pressing to adhere the breading to the eggplant.
Spray the breaded eggplant with cooking spray and then place it, sprayed side down, in the air fryer basket or pan. Be careful not to overlap the eggplant so it cooks and browns evenly. Spray the tops of the eggplant slices with cooking spray.
Air fry at 370 degrees F for 6 minutes. After 6 minutes, remove the basket, flip the eggplant, spray again with cooking spray and return to the fryer and cook for another 6 minutes at 370 degrees F.
Remove the basket and top each eggplant slice with 1-2 tablespoons of tomato sauce and a slice of mozzarella cheese or 2 tablespoons of shredded mozzarella cheese and a few tablespoons of Parmesan cheese.
Return to air fryer and air fry for 3-4 minutes at 370 degrees F or until cheese is melted and browned.
