Preheat broiler. Shape ground beef into eight 1/4 inch thick patties. Place one cheese slice on top of each of four of the patties; sprinkle with crumbled bacon. Place remaining four patties on top of the bacon and cheese topped patties. Seal edges well.

Place the patties on the unheated rack of a broiler pan. Broil 3-4 inches from the heat for 10 to 12 minutes or until done, turning patties once half way through cooking. Place one of each remaining four cheese slices on tip of patties. Broil for 1 minute.

Meanwhile, spread cut sides of toasted buns with the onion dip. Serve burgers on prepared buns.