Preheat oven to 350 degrees F.
Bake bread cubes in a single layer on a large baking sheet for about 20 minutes until golden. Cool and place bread cubes in a large bowl.
In a large skillet over medium-high heat, cook the sausage, crumbling with a wooden spoon, until brown and cooked through. Transfer the cooked sausage to a plate lined with a paper towel to soak up the extra grease.
In the same pan you cooked the sausage, drain the excess grease and add 2 tablespoons of butter (or olive oil) to the pan. Add in the onion, fennel and celery and sauté everything for about 7 minutes until veggies are crisp and tender, stirring occasionally. Stir in the chopped apple and garlic, sautéing for and additional 5 minutes until veggies are tender. Add the sage and cook for one more minute, turn off the heat and mix in the fresh parsley.
In a large bowl, mix together the toasted bread cubes, cooked sausage, and sautéed veggies. In a smaller bowl, whisk together the chicken broth, apple cider, egg, salt and pepper and gently combine the egg mixture with the bread mixture. Feel free to add more chicken broth, as needed, if the stuffing seems too dry.
Spoon the stuffing into an 13 x 9-inch baking dish coated with cooking spray and bake at 350 degrees F covered for about 35 minutes, then remove the foil and continue baking an additional 10 minutes until top is golden and stuffing is set. Serve and enjoy!