Preheat the oven to 400 degrees F. Grease a rimmed baking sheet with cooking spray. Place the grated Parmesan on a dinner plate and add the garlic powder and paprika.
Wash the lemon and pat it dry. Cut it in half and make zest from one of the halves by using a zester or grater to shave off the yellow part of the skin, adding it to the cheese mixture.
Rinse the parsley and pat it dry. Cut it with scissors or chop it before adding it to the cheese mixture. Toss the cheese mixture with a fork to blend it.
Rinse the fish in cold water and rub your thumbs along the surface to see if there are any bones to remove. Pat the fish dry with paper towels.
Melt the butter in a small pan on the stove or microwave it in a bowl. Set up an assembly line from left to right with the fish, the butter, the cheese mixture, and the sheet pan.
Use a fork to dip each piece of fish in the butter on both sides, then in the cheese mixture, coating both sides and patting the topping onto the cod with the fork. Place the coated fish onto the sheet pan, top with any excess melted butter and bake for 15 minutes. The cod is done when it can be easily flaked with a fork.
Squeeze lemon juice over the fish and serve with bread for dipping in the garlic butter (you can place the pan on the table for informal dinners) or spoon the butter over rice, mashed potatoes or polenta. Store leftover cod in the refrigerator for up to three days.
* I use salted butter and find this dish is salty enough with the Parmesan. If you're using unsalted butter, you'll need to add salt.To prep in advance for companyEarlier on the day you want to serve it, dip the cod fish in the melted butter and coat it with the Parmesan mixture. Then, refrigerate it in a single layer, covered lightly with foil instead of plastic wrap, which would stick to the coating.Remove the pan(s) of fish from the fridge 15 minutes before the cod needs to go in the oven. You might need to bake the cod slightly longer than 15 minutes if your pans are chilled, so just cut into one of the thicker pieces to see if it’s ready.Substitutions
Use one garlic clove chopped or pressed instead of the garlic powder.
Use dried parsley or dried basil instead of fresh parsley.
Use bottled lemon juice if you don't have fresh.
Use haddock or another thick white fish instead of cod.
If you don't have paprika, add a little black pepper after the fish is cooked.
If you don't have fresh cod, you can use frozen. Just make sure it's thawed completely and patted dry first.