Heat oven to 325 degrees. Grease 2 quart, 3-inch deep casserole dish by rubbing raw bacon around the bottom and sides.
Slice the bacon into bite-sized pieces.
Pour one can of pork and beans into the dish.
In small bowl combine sugar and mustard; sprinkle half the mixture over the beans. Top with the remaining beans. Sprinkle the rest of the sugar-mustard mixture over the beans. Top with the chopped bacon and ketchup. Bake uncovered 2 1/2 hours.
Notes: The recipe may be multipled for more servings. Check on the beans as it nears completion. It should have a bubbling rich brownn look at the end. May add a little water if it seems to thick.