Method
Preheat your oven to 400°F (200°C) and lightly grease a 9x13 inch baking dish with butter or non-stick cooking spray.
Pat the cod fillets completely dry with paper towels and arrange them in a single layer in the prepared baking dish.
In a small bowl, whisk together the melted butter, lemon juice, garlic powder, smoked paprika, salt, and black pepper until well combined.
Pour the butter and spice mixture evenly over the top of each cod fillet, using a spoon to coat them thoroughly.
Place 1 or 2 thin lemon slices on top of each seasoned fillet.
Bake for 12-15 minutes, or until the fish is opaque throughout and flakes easily with a fork. The internal temperature should reach 145°F.
Carefully remove the baking dish from the oven and sprinkle the baked cod with the chopped fresh parsley before serving.