Pour milk mixture over the bread, cover with foil and refrigerate overnight.
In the morning remove from refrigerator and uncover. Preheat oven to 350. Melt 1 tablespoon butter in microwave and brush top. Mix 2 tablespoons sugar with 1 teaspoon cinnamon and sprinkle on top.
Bake until golden brown. About 40 minutes. Helpful hint, the bread will puff up some near the end. When the center is puffed, that is the minimum time but it will be soggy still. Go a little longer to get a dryer casserole.
Allow to cool for 5 – 10 minutes before serving. Top with maple syrup if you want or a dusting of powder sugar.
This recipe is easily doubled. Use a 9 by 13 pan. The baking time will be perhaps 10-15 minutes longer. The topping might get browner than you want so tenting some with foil near the end will prevent that.
If you want more of a bread pudding type texture then you could bake a little shorter but be sure to get to at least 165 internal temperature for food safety due to the eggs.