In a liquid measuring cup with a spout, stir together the buttermilk and 1 teaspoon Old Bay. Add the fish to a large ziptop bag and pour the buttermilk mixture over the top. Tightly seal the bag removing as much air as possible, and turn several times to coat the fish. Place the bag on a plate to catch any drips and refrigerate for 20 minutes to marinade.

Meanwhile, set up your stations: In a wide, shallow dish (a pie dish works well), place the flour. In a second dish, briskly whisk the egg until very well blended. In a third dish, stir together the Panko and the remaining 2 teaspoons Old Bay.

Working one fillet at a time, remove the fish from the marinade, shake off any excess, then dip in the flour, coating all sides, then the egg (let the excess drip off), and finally dip in the Panko. Press the Panko onto the fish’s surface as needed so that it sticks to all sides. Place on a plate or parchment lined baking sheet, then repeat with the remaining fish.

Coat your air fryer basket with nonstick spray. Add the fillets in a single layer so they are not touching (you may need to cook in batches), lightly mist the tops with nonstick spray, then air fry the fish at 390°F for 10 to 12 minutes, flipping it over around the 6-minute mark. When the fish is done, it should be firm, flake easily with a fork, and register 145°F on an instant read thermometer.

If desired, place the fish on a wire rack set on top of a baking sheet and keep it warm in a 250°F oven between batches. Repeat with remaining fish. Serve hot with lemon wedges, tartar sauce, and a sprinkle of fresh parsley.