Spread 3 tablespoons butter on bread slices. Trim and discard crust; cut slices into cubes.
Beat eggs in a large bowl; stir in bread, sugar, milk, raisins, 2 tablespoons butter, and vanilla. Pour into a greased 1 1/2-quart casserole. Place casserole in a pan of warm water. Bake at 300° for 50 minutes or until a knife inserted in center comes out clean. Cool; serve with Lemon Sauce.