Spray a 9 x 13 inch casserole dish with cooking spray. Arrange bread slices in the bottom of the dish. You will have bread leftover which you can use to make a second casserole, for bread crumbs, or garlic bread later.

In a large bowl, combine eggs, milk, vanilla, cinnamon and nutmeg. Whisk together until well mixed. Pour over bread slices, coating each slice. Cover and refrigerate overnight.

The next morning, preheat oven to 350°. While the oven is heating, combine the butter and brown sugar in a small saucepan. Melt over medium heat and cook until bubbling. Add maple syrup and stir well. Pour mixture over bread and egg mixture.

Bake at 350° for 40 minutes.