Preheat oven to 375 degrees F. In a large bowl stir together sauerkraut, onion, dried parsley, and caraway seeds. Spread sauerkraut mixture in the bottom of a 3-quart rectangular baking dish. Top with 1 1/2 cups of the cheese and 2/3 cup of the salad dressing. Add corned beef. Top with the remaining 2/3 cup salad dressing and another 1 1/2 cups of the cheese.
Brush bread slices with melted butter. Arrange bread on top of layers in baking dish.
Bake about 35 minutes or until heated through and bread is toasted. Top with the remaining 1 cup cheese. Bake about 5 minutes more or until cheese is melted.