Preheat oven to 300°F. Place bread cubes on baking sheet. Bake 20 minutes or until lightly toasted and dried, stirring occasionally. Remove from oven. Increase oven temperature to 325°F.
Meanwhile, melt butter in large skillet on medium heat. Add celery and onion; cook and stir 5 minutes or until softened. Stir in apples and cranberries.
Toss bread cubes with celery mixture, stock, sage and sea salt in large bowl until well mixed. Spoon into lightly greased 13x9-inch baking dish.
Bake 30 minutes or until heated through and lightly browned.