Coat cod fillets in a crunchy topping to add a contrasting texture to the tender fish. Place breadcrumbs or crushed crackers in a shallow bowl. In a separate bowl, add a wet dredging ingredient such as whisked egg or mayonnaise. Spray a foil-lined baking sheet with cooking spray and arrange the cod fillets in a single layer. Season the fish with salt and pepper, and brush the egg over the top and press the crumbs into the top of each fillet. Bake it in an oven that’s been preheated to 400 degrees Fahrenheit for approximately 10 minutes, or until the flesh is opaque and flaky. Raise the oven rack to broil the fish 2 inches from the heat source to brown the crumbs if necessary.