Preheat your oven to 400°F (200°C).
Butter a 9×13 inch baking dish generously.
Pat cod fillets completely dry using paper towels. Season both sides with salt and pepper.
Place your seasoned cod fillets in the prepared baking dish, ensuring there’s space between each piece.
Melt butter in a small saucepan over medium heat until foaming. Stir in panko breadcrumbs, chopped parsley, garlic powder, and lemon zest until everything resembles wet sand.
Evenly divide the breadcrumb mixture over each cod fillet, pressing gently to adhere.
Drizzle the top of each fillet with fresh lemon juice and olive oil.
Place your baking dish in the preheated oven and bake for about 12–15 minutes until the fish flakes easily with a fork and the topping is golden brown.
Let your Boston Baked Cod rest for about two minutes before serving.