Dry the cod fillets thoroughly with paper towels to remove any moisture.
Brush both sides of the fillets lightly with olive oil.
Season the fillets evenly with salt, freshly ground black pepper, and garlic powder on each side.
In a shallow dish, mix together grated Parmesan, panko breadcrumbs, lemon zest, and a pinch of salt until combined.
Press each cod fillet into the Parmesan-panko mixture, ensuring the coating sticks firmly and uniformly.
Set the coated fillets aside on a plate and let them rest for 3 to 5 minutes to help the crust bind better.
Preheat your air fryer to 400°F (200°C) for about 3 minutes before cooking.
Lightly spray the air fryer basket to prevent sticking and arrange the cod fillets in a single layer without overlapping.
Air fry the fillets for 6 minutes, then carefully flip them over using a spatula.
Continue cooking for an additional 4 to 5 minutes until the fish turns opaque, flakes easily, and the crust is golden brown.
While the cod rests for 2 minutes after cooking, whisk together the melted butter with a squeeze of fresh lemon juice.
Drizzle this lemon butter over the hot fillets.
Sprinkle fresh chopped parsley on top and serve each fillet with lemon wedges on the side for added brightness.