This recipe is from www.seafood.allrecipes.com and was posted by snoochums95. It is by far my favorite recipe I have found online and integrated into my "easy and regularly cooked recipes" and I wanted it on my favorite recipe site!
In a bowl, mix the spinach, 1/2 cup Cheddar cheese, about 5 tablespoons dry bread crumbs, and the egg. Spread the mixture into the bottom of a small baking dish. Arrange the cod fillets on top of the spinach mixture, and season with salt and pepper. Top with the remaining Cheddar cheese and bread crumbs.
Cover, and bake 20 minutes in the preheated oven, or until fish flakes easily with a fork.