Preheat oven to 300 degrees F. Divide bread cubes between 2 rimmed baking pans. Transfer to oven and bake 12 minutes. Transfer bread cubes to large bowl. Increase oven temperature to 375 degrees F.

Meanwhile, in large skillet, cook bacon over medium heat 6 to 8 minutes or until crisp, stirring frequently. Use slotted spoon to transfer bacon to bowl with bread cubes. Reserve bacon fat in skillet.

Add celery, fennel and onion to skillet. Cook over medium-high heat 4 to 6 minutes or until slightly softened. Stir in apples, parsley, rosemary, thyme, salt and pepper. Cook 3 minutes longer, then remove from heat.

Spray 9 x 13-inch baking dish with cooking spray. Add broth, milk and vegetable mixture to bowl with bread cubes. Toss until well combined.

Transfer mixture to prepared baking dish and cover with foil. Transfer to oven and bake 30 minutes. Remove foil and bake 30 minutes longer or until top is golden brown. Let stand 10 minutes before serving. Serve garnished with chopped fennel fronds.