Turn on the oven to preheat to 180 degrees. Grease all slices of bread on one side with butter and cut each slice into 4 equal parts. Place half of the bread, butter side down, in a large ovenproof dish.
In a large bowl, combine plums with lemon juice. Place these plums on bread slices in a mold, sprinkle with dried cherries on top. Place the remaining slices of bread on top of the cherries.
In a large bowl, lightly beat eggs with milk and sugar. Pour this mixture over the bread in the form, press down with a spoon so that the bread drowns in the milk and absorbs most of it.
Place the dish in the preheated oven and bake the casserole for 45-50 minutes. Allow the finished bread casserole to cool at room temperature for 30 minutes. Serve warm bread casserole with sour cream, sprinkle with powdered sugar and nuts (optional).