Preheat oven to 300 degrees. Transfer bread cubes to two rimmed baking sheets and spread into an even layer.
Place both sheets on two opposite oven racks (set near center) of preheated oven and allow to dry through, tossing bread cubes and rotating baking sheets to opposite racks once halfway through baking, about 30 minutes total.
Remove from oven and set aside. Increase oven temperature to 325 degrees.
Melt butter in a large skillet over medium heat. Add celery and onion, season lightly with salt and saute until softened, about 10 - 13 minutes.
Add in apples and saute until they begin to break down and soften slightly, about 3 - 4 minutes. Remove from heat, toss in cranberries, 3 Tbsp parsley, rosemary, thyme and sage.
Pour dried bread cubes in an extra large mixing bowl. Pour apple mixture over bread cubes, season lightly with salt to taste then evenly pour in 1 cup of the chicken broth and gently toss mixture.
Slowly pour in more broth as needed (and gently toss) until bread has nearly soaked entirely through**.
Spray a 13 by 8-inch baking dish with non-stick cooking spray. Pour bread mixture into baking dish and gently spread into an even layer.
Cover baking dish with foil and bake in preheated oven 15 minutes then uncover and bake until warmed through and top is golden brown, about 15 - 25 minutes longer. Serve warm sprinkled with remaining 1 Tbsp parsley.
*I recommend using a brand such as Great Grains, Granny Sycamore or Granny's Delight. Don't use that super airy sandwich bread. It is too delicate and won't absorb much liquid. If you don't have the time to dry your own you can use 8 cups of the store-bought unseasoned bread cubes - the freshly dried are better though and you can dry them a few days before you need to use them (or even weeks and freeze them).
I used the full 2 cups broth but only add as much as it takes to moisten the bread, all brands are a little different. You can also add a little more if you need more but don't overdue it.
Recipe source: inspired by a bookmark I saw in Food Network Magazine from McCormick