Slice bread into 1/2 inch slices.
Spray 13x9" glass pan with no-stick spray.
Place bread in dish, placing tightly together.
In separate bowl, beat eggs, 1/2 cup sugar,
milk, and vanilla. Pour half the mixture over bread.
Peel, core, and slice apples; place on top of bread.
Pour remaining egg mixture over apples.
Mix cinnamon and sugar; sprinkle over apples.
Dot with butter; cover, and refrigerate overnight.
Bake 1 hour for 350F uncovered. Let rest.