Preheat the oven to 300°F (150°C). Spread the bread cubes in a single layer on a sheet pan and bake for 7 minutes until slightly crisp. Remove from the oven, transfer the bread cubes to a large mixing bowl, and increase the oven temperature to 350°F (175°C).
In a large sauté pan over medium heat, melt the butter. Add the diced onions, celery, apples, parsley, salt, and pepper, and cook for about 10 minutes until the vegetables are tender. Transfer the mixture to the bowl with the bread cubes.
Using the same sauté pan, cook the sausage over medium heat for approximately 10 minutes, breaking it up with a fork, until it is browned and thoroughly cooked. Add the sausage to the bread and vegetable mixture.
Pour the chicken stock over the bread mixture, then add the dried cranberries. Mix thoroughly to combine all the ingredients. Transfer the stuffing mixture into a 9x12-inch baking dish.
Bake in the preheated oven at 350°F (175°C) for about 30 minutes, until the stuffing is golden brown on top and heated through in the center. Serve warm.