1Generously spray 2 1/2-quart casserole or 13x9-inch baking dish with cooking spray. In large bowl, beat flour, milk, granulated sugar, orange peel, vanilla, salt and eggs with electric mixer on medium speed about 2 minutes or until smooth. Stir in bread cubes until coated.
2Pour bread mixture into casserole. Top evenly with orange segments. Cover; refrigerate at least 8 hours but no longer than 24 hours.
3Heat oven to 400°F. Uncover; bake 20 to 25 minutes or until golden brown. Sprinkle with powdered sugar. Serve with orange marmalade.