Set the oven to 425 degrees Fahrenheit. Use nonstick spray sparingly to a baking pan.

Combine the butter, lemon juice, garlic, salt, and red pepper flakes in a small bowl. Add the capers and stir.

Cod fillets should be put in the baking dish. On top, spread the butter mixture. If necessary, spread the thick sauce on the tops of the fillets in a uniform layer using a brush. They're covered in paprika.

Bake until the fish is completely done, opaque, and flakes with a fork with no difficulty. This should take around 15 minutes, depending on the thickness of the fish fillets and your oven (25 minutes if using frozen fish).