Preheat your oven to 350°F (175°C).
In a medium pan, melt the butter over medium heat. Add the chopped celery and onion (if using), and sauté until softened, about 5-7 minutes.
In a large mixing bowl, combine the Mrs. Cubbison’s Stuffing Mix with the sautéed vegetables.
Pour the chicken broth over the stuffing mixture and stir to coat the bread cubes evenly. Add the melted butter and mix well.
Transfer the stuffing mixture into a greased 9x9-inch baking dish and spread it out evenly.
Cover with aluminum foil and bake for 25 minutes.
After 25 minutes, remove the foil and bake for an additional 10-15 minutes, or until the top is golden brown and crispy.
Remove from the oven and serve hot. Enjoy!