Spread sauerkraut in ungreased rectangular pan 13 by 9 by 2 inch. Arrange tomato slices over sauerkraut, spread with dressing and dot with 2 tablespoons butter. Top with corn beef and cheese. Bake 15 minutes. Mix baking mix, cracker crumbs, 1/4 cup butter, the cocoa, molasses and caraway seeds. Add milk, stir with fork into dough. Beat 30 seconds, smooth into ball on surface dust with baking mix, knead 10 times. Roll 1/2 inch thick. Cut with biscuit cutter.

Arrange biscuits evenly over top of casserole. Bake 15 to 20 minutes at 425 degrees. Serve with quick mustard sauce.