Preheat oven to 325 degrees F. Coat soufflé dish with baking spray and then with sugar.
Separate eggs. Whisk egg whites until soft peaks form and set aside. Mix sugar and yolks in a double boiler. Whisk over simmering water. While whisking continuously, slowly and steadily pour melted butter into the egg and sugar mixture. Whisk until butter is fully incorporated and mixture has thickened.
Remove from heat and stir in flour and Butterkäse. Fold egg whites into batter.
Fill coated soufflé dish with batter. Drain cherries from marinade, drop them into batter and allow them to sink.
Bake at 325 degrees F for 25 minutes or until the soufflé puffs and the top is golden brown.