Place the bread cubes in a single layer on a large baking sheet and bake for 7-10 minutes, or until dried and toasted. Turn the oven up to 350 degrees F.
While the bread is toasting, cook the sausage over medium heat in a large skillet until browned and cooked through, about 10 minutes. Break up the sausage with a wooden spoon or spatula while cooking. Drain the excess grease off of the sausage and place the sausage on a plate that has been lined with paper towels.
In the same pan, melt the butter and add the onions and celery and cook until tender, about 5 to 7 minutes. Add the garlic, parsley, sage, salt and pepper. Cook for 3 to 5 minutes or until garlic is cooked but not browned.
In a large bowl, combine toasted bread cubes, cooked sausage, and the vegetables. Pour the chicken broth over the mixture and stir until well combined and the liquid has been absorbed. Stir in the dried cranberries, if using.
Pour the stuffing into a greased 9x13-inch baking dish. Bake for 30 to 35 minutes, or until browned on top and heated through. Serve warm.