2Place the bread in a large bowl, pour in the milk and soak until soft. Mash well, then mix in the ham, beef, eggs, salt, dry mustard, and 1/3 cup of brown sugar. Mix thoroughly and pack the mixture into a 9x13 glass baking dish. Stir together 1 cup of brown sugar, flour, and prepared mustard. Stir in enough vinegar to make a spreadable paste. Spread the topping over top of the meat.
3Bake in preheated oven for one hour until the ground beef has cooked, and the topping has browned nicely.