Melt the first amount of butter in a large skillet. Add onion and celery and cook over medium heat, stirring occasionally, until soft, about 8 minutes. Add garlic and cook 2 minutes more.
Place breadcrumbs in a large mixing bowl. Add parsley, rosemary and sage. Season with salt and pepper. Set aside.
In a small saucepan, combine the second amount of butter and chicken broth. Warm over medium heat until butter melts.
Add onion and celery mixture to breadcrumbs. Slowly add chicken broth, stirring gently to combine.
Add chopped apple and toss.
If baking, transfer to a baking dish and cook at 350 degrees F for 30-40 minutes, or until golden brown and cooked through. Alternatively, you can place in crockpot on low heat and cook for 4-6 hours, stirring halfway through process. You can add more broth or turkey drippings if you find it too dry.