Cut bread into ½" cubes.Coat muffin pan with butter.Divide bread between all 12 muffin cups.Whisk together the milk, eggs, sugar, vanilla, and cinnamon until blended.Slowly add about 1½ oz of liquid over bread in each cup. I use a baster to make this easy.Cover and refrigerate for several hours.Preheat oven to 350.Combine butter, brown sugar, flour and cinnamon.Mix until you have a well blended crumbs.Cover the muffins evenly with this topping.Bake for 25 minutes or until tops are golden brown.Let cool for 10 minutes.