Butter a 9×13 baking dish. Arrange the slices of bread in the bottom. In a large bowl, beat together eggs, milk, cream, vanilla, and cinnamon. Pour over bread slices, cover, and refrigerate overnight.
The next morning, preheat oven to 350*. In a small saucepan, combine butter, brown sugar, and corn syrup; heat until bubbling. Pour over bread and egg mixture.
Bake in preheated oven, uncovered, for 40 minutes.