To back stuffing separately from chicken or turkey, preheat oven to 400°F. Grease an oblong baking dish, approximately 10 x 13".
Set a 6-quart stock pot on stove, add oil and heat over medium heat. Add onion and celery; cook until onion is tender, approximately 7 minutes. Add thyme, sage, and pepper; cook until fragrant, about 30 seconds.
In a small bowl whisk together eggs, salt, and 7 tablespoons chicken broth (4 tablespoons if cooking inside turkey).
Off heat, to mixture in stock pot, stir in about 2 cups bread cubes, diced apples, and cranberries. Incorporate whisked egg mixture. Add remaining bread cubes. Toss to uniformly combine.
If not cooking inside turkey, turn mixture into baking dish, cover with foil, and bake until apples are cooked, about 25 - 30 minutes.
If stuffing a turkey, line cavity with cheese cloth, to be able to pull out easily later. Pack stuffing into turkey just before putting turkey in the oven. Extra stuffing can be baked separately in a pan as described above. Make sure stuffing inside turkey reaches 165°F before removing from oven. Before serving, toss together to combine the stuffing cooked inside the turkey with that baked in the pan.