Warm the air fryer up to 350 F. Get it up to temp before you slice up the zucchini.

Mix up the panko and cheese on a plate. Dip a zucchini slice into the beaten egg, then into the cheesy crumbs, giving it a press to coat. Place the slice on a wire baking rack, then repeat until all of the slices are coated. Give the slices a light spray with the cooking spray.

Place the zucchini slices into the air fryer basket. Try to get all of them in there at once, but make sure they don't overlap. If you don't have room for all of them, just set the leftovers aside for the moment.

Cook the slices for 10 minutes. Flip 'em over with heat-safe tongs, then cook again for an additional 2 minutes. Take the slices out of the fryer. If you couldn't get them all in there in one go, repeat the cooking process with the remaining zucchini slices.