Break bread into small pieces into an 8 inch square baking pan. Drizzle melted butter or margarine over bread. If desired, sprinkle with raisins.
In a medium mixing bowl, combine eggs, milk, sugar, cinnamon, and vanilla. Beat until well mixed. Pour over bread, and lightly push down with a fork until bread is covered and soaking up the egg mixture.
Bake in the preheated oven for 45 minutes, or until the top springs back when lightly tapped.
