Mix all together, put in a covered casserole, lay two strips bacon on top, bake covered in 375F oven for 30 minutes, and then remove the cover and cook for another 30 minutes.
I usually skip the bacon and add some pulled pork if I have some in the refrigerator.
40 ounces canned baked beans -- drain
1/4 cup chopped onions
1/4 cup ketchup
1/2 cup molasses
2 tablespoons prepared mustard -- (yellow or brown)
2 strips bacon -- partially cooked, -- chopped