Preheat the oven to 375°F. Grease a muffin tin with cooking spray or olive oil.
In a large skillet over medium heat, heat the olive oil. Add the diced onion and cook until softened, about 3-4 minutes. Stir in the minced garlic and cook for an additional minute.
Add the pork sausage to the skillet, breaking it apart with a spatula. Cook until browned and cooked through, about 5-7 minutes. Drain excess fat if necessary.
Stir in the diced apples, pancetta, sage, thyme, salt, and pepper. Cook for another 3-4 minutes until the apples are slightly softened.
In a large bowl, combine the bread cubes and sausage mixture. Pour in the chicken broth and beaten egg, mixing until everything is well combined.
Spoon the mixture into the prepared muffin tin, filling each cup to the top. Bake for 20-25 minutes, or until the tops are golden brown and crispy.
Let the stuffing cups cool for a few minutes before removing them from the muffin tin. Garnish with fresh parsley if desired.