Possibly the best meatloaf ever

I made this with my mother-in-law when we were cooking one day and Jordan and I were very sad when they were gone from our freezer.

Meaty mixture:
2 pounds of ground beef
1/2 cup bread crumbs or saltine cracker crumbs
1/2 cup graham cracker crumbs
2/3 cup milk
1/4 cup of onion, chopped finely
2 eggs
1/2 tsp pepper
1pkg or 3 tbsp onion soup mix

Sauce:
1/4 cup brown sugar
1Tbsp dry mustard
1/2 cup ketchup


Place meat and sauce on top in an 8x8 pan and bake @350 for an hour uncovered