Preheat oven to 350 degrees. Generously spray or grease a 9 X 11 baking dish.
Prepare cornbread (from scratch or Martha White yellow, not sweet). Crumble cornbread into very small pieces a large bowl.
Melt butter (or add olive oil) in a large sauté pan or skillet and sauté onions, celery, and oysters on medium heat until vegetables are translucent and oysters are cooked through, about 8 minutes. In a small bowl, whisk eggs.
Add eggs, onions, celery, oysters, broth, white bread cubes, Creole or poultry seasoning, mushroom soup, salt and pepper to the cornbread and stir. Mix thoroughly and spoon into prepared casserole dish. Place in pre-heated oven and bake for 35 – 40 minutes or until golden.
Garnish with parsley sprigs, fresh sage, or green onion slices if desired.