Soak bread in just enough water to soften bread.  Let stand until soft; drain.  Using hands, squeeze water out of bread; mix thoroughly.  In a small bowl, mix together butter or margarine, sugar, egg, vanilla & milk; cream together until blended.  Combine the 2 mixtures & add raisins.  Turn into a 7 1/2 x 11 1/2 x 2 1/2" baking pan.  Bake 1 hour and 45 minutes at 350° or until knife inserted in center comes out clean.  This can be eaten plain or with a mound of whipped cream or whipped topping.  12-15 servings.