Preheat the oven to 325 degrees . Scatter the bread on a baking sheet and season with the poultry seasoning. Toast in the oven until golden, 10 to 12 minutes. Set aside.
In a large skillet, melt 3 tablespoons butter over medium heat. Add the apples, onions, celery and bay leaf, season with salt and pepper and cook until tender, 7 to 8 minutes. Stir in the chicken, parsley and 2 cups chicken broth and cook until heated through, 3 to 4 minutes. Stir in the bread cubes.
In a small saucepan, melt the remaining 2 tablespoons butter over medium heat. Whisk in the flour for 1 minute, then whisk in the remaining 2 cups chicken broth. Season the gravy with salt and pepper.
Discard the bay leaf. Serve the stuffing in large shallow bowls, topped with the gravy.