In a large skillet set over medium-high heat, brown the sausage. Use a potato masher to press the sausage in the pan. It assures a nice crust forms on the sausage. Then, using a wooden spoon, break apart the sausage as it cooks. Once the sausage is brown, add in the celery, apples and onion and saute until fragrant and softened, about 5 minutes. Add in the parsley, sage and thyme, and then add the chicken stock and scrape up any brown bits that have formed on the bottom of the pan. Season with pepper, turn off the heat and set aside.
Add the bread cubes to a large mixing bowl and add the sauteed sausage and vegetable mixture. Toss to combine, and then add in the dried cranberries. Once the mixture has cooled slightly, add in the eggs and toss until all ingredients are combined.
Line each cup of 2 nonstick muffin pans with 2 slices prosciutto. Let the prosciutto hang over the cups. As they bake, this becomes crispy and delicious, plus the prosciutto shrinks up a bit as it cooks as well. Press the prosciutto slices into the muffin cups to create space for the stuffing.
Once the muffin cups are lined, fill each cup with a heaping amount of stuffing.
Bake the stuffing cups until golden brown on top and the prosciutto is nice and crispy around the sides, 20 to 25 minutes. Once cooked, remove from the oven and let cool in the muffin tins until they are cool enough to touch, 5 to 10 minutes.