Preheat the oven to 400F. Lightly spray a baking sheet with oil and set aside.
Set up the flour, beaten egg, and breadcrumbs in it's own individual dish. This will be your breading system.
Season with flour with the garlic powder, salt, and pepper. Season with breadcrumbs with salt and pepper.
Take the sliced cod pieces and dust each piece with flour, then the egg, and finally the seasoned breadcrumbs. Shake off any excess and repeat with the rest of the fish.
Bake on the prepared sheet tray for 12 minutes or until golden brown.