Line a baking dish with parchment paper for easy cleanup.
In a small bowl, combine the melted butter, lemon juice, lemon zest, minced garlic, oregano, paprika, salt, and pepper. Mix well to create the lemon butter sauce.
Place the cod fillets in the prepared baking dish, skin-side down.
Pour the lemon butter sauce evenly over the cod fillets, making sure they are well coated.
Bake in the preheated oven for 12-15 minutes, or until the fish is opaque and flakes easily with a fork.
Once baked, remove from the oven and let it rest for a minute.
Garnish with freshly chopped parsley and serve with lemon slices on the side.