Prep the Fish: Pat cod fillets dry with paper towels. Season both sides with salt and pepper.
Mix the Coating: In a bowl, combine breadcrumbs, Parmesan, garlic powder, onion powder, oregano, paprika, salt, and pepper.
Make the Sauce Base: In a small bowl, whisk together mayonnaise, Dijon mustard, and lemon juice.
Coat the Cod: Brush one side of each fillet with the mayo mixture, then press firmly into the breadcrumb mix until well coated.
Air Fry: Preheat air fryer to 400°F (200°C) for 5 minutes. Spray basket lightly with oil. Place fillets in a single layer, without overcrowding.
Cook: Air fry for 10–12 minutes, flipping halfway. Fish is ready when crust is golden brown and internal temp reaches 145°F (63°C).
Serve: Garnish with chopped parsley. Serve hot with lemon wedges, roasted veggies, or a fresh salad.