Heat large skillet over medium heat; cook pancetta about 5 minutes, or until golden brown and lightly crisped. Stir in butter until melted. Cook celery, onion, apple, garlic, sage, thyme, rosemary, salt and pepper, stirring frequently, 8-10 minutes, or until vegetables soften. Let cool slightly.
Stir celery mixture with bread; toss with broth until moistened. Transfer to buttered 9-inch square baking dish. Sprinkle with Parmesan and parsley.
Cover with foil; bake 20 minutes. Remove foil; bake 10-15 minutes, or until set in center and golden brown on top. Let stand 5 minutes.