Heat oven to 350°. Generously butter or mist with cooking spray a 9 x 13-inch baking dish.
In a large bowl, toss together the stuffing mix and crumbled bread.
Warm butter in a medium saucepan over medium-high heat. Stir in onion and celery and cook until almost tender, about 5 minutes. Stir in salt, pepper, and poultry seasoning, and cook 2 minutes more. Pour into bowl with Pepperidge Farm mixture and toss well.
In a medium bowl, whisk together cream of chicken soup and eggs. Stir into dressing mixture.
Stir in enough broth to give the dressing mixture the consistency of cooked oatmeal. Pour into prepared baking dish.
Bake until set and browned on top, about 45 minutes. Let stand for at least 10 minutes before cutting into squares and serving warm.