Pat dry cod of any excess moisture with a paper towel.
Slice the butter into cubes and place a couple of pieces on the bottom of the baking dish. Top the butter cubes with the cod fillets and season the fish with garlic parsley salt.
Add another layer of butter cubes on top of the cod, followed by thick slices of lemon.
Bake the cod at 425°F for about 15 minutes (this will vary depending on the thickness of your fillets).