Heat oven to 350 degrees F. Coat a 13 x 9 x 2-inch baking pan with nonstick spray.
Place a large nonstick skillet over medium-high heat. Remove casings from sausage and crumble into skillet. Cook 7 minutes or until no longer pink. Remove sausage to a large bowl with a slotted spoon.
Add butter to skillet. Add leeks, celery, and 1/4 teaspoon each of salt and black pepper and cover. Cook, stirring occasionally, for about 10 minutes or until softened.
Stir in Granny Smith apples, dried thyme; and the rest of the salt and pepper; cook 5 minutes, stirring occasionally.
Add to sausage. Stir in bread, chicken broth, half-and-half and parsley.
Pour mixture into prepared pan and bake at 350 degrees F for 50 minutes or until lightly browned on top.
