Mix bread and cherries in bowl. Bring milk and sugar in saucepan to boiling. Stir in chocolate until almost melted. Remove from heat; stir until smooth. Cool to room temperature.
Whisk eggs and white in small bowl. Add to chocolate. Pour over bread. Cover; let stand 30 minutes.
Butter 11 x 7 x 2-inch baking pan. Pour bread mixture into pan. Cover tightly with buttered aluminum foil.
Bake in preheated 325°F oven 30 minutes. Remove foil; cool slightly. Dust with sugar and serve with whipped cream if you wish.