01 - Preheat the oven to 400°F. Line a baking sheet with parchment paper or lightly grease it.
02 - Gently pat the cod fillets dry with paper towels. Season both sides generously with salt and freshly ground black pepper. Arrange the seasoned fillets evenly on the prepared baking sheet.
03 - In a small mixing bowl, whisk together the Dijon mustard and mayonnaise until thoroughly combined. Using a pastry brush, evenly coat the top surface of each cod fillet with this mixture.
04 - In a separate mixing bowl, combine the panko breadcrumbs, melted unsalted butter, chopped fresh parsley, lemon zest, garlic powder, and paprika. Mix well until all ingredients are uniformly distributed and the panko is moistened.
05 - Carefully press the prepared panko mixture onto the mustard-coated side of each cod fillet, ensuring a thick, even layer that adheres securely.
06 - Transfer the baking sheet to the preheated oven and bake for 15 to 18 minutes, or until the panko crust achieves a golden-brown crispness and the fish flakes easily when tested with a fork.
07 - Remove from oven and serve the baked cod immediately, accompanied by fresh lemon wedges for a bright, zesty finish.