For the sausage, place the turkey in a bowl and season evenly with poultry seasoning and salt and pepper, if not included in the spice blend. Add the remaining ingredients and mix to combine well. Refrigerate several hours or overnight.
In a large skillet, heat a drizzle of EVOO over medium-high heat. Add the sausage meat and brown and crumble with a potato masher; remove to a plate.
Add the butter to the skillet and reduce the heat to medium. When the butter foams, add celery, apples, onions and bay leaf and season with salt and pepper. Cook to soften, 10 minutes, then add the stuffing cubes or croutons. Moisten with stock and season with poultry seasoning; combine with the sausage.
Grease a baking dish with the softened butter. Fill with the stuffing and dot the top of the stuffing with butter as well.
To serve, pre-heat the oven to 425ºF. Bake the stuffing just long enough to crisp up the top and warm the stuffing through, 20-25 minutes if at room temperature, and serve.