In a large bowl, combine ground chuck, sour cream, ranch dressing mix, cooked bacon, and shredded cheddar cheese. Mix gently until all ingredients are evenly incorporated but do not overwork the meat. Divide the mixture into 4 equal portions and form each into a patty, about ¾ inch thick. Preheat a skillet or grill over medium-high heat. Cook the patties for 4-5 minutes on each side or until desired doneness is reached and cheese is melted. Toast the hamburger buns lightly on the grill or in a toaster. Assemble burgers by placing each patty on the bun, then top with lettuce, tomato, mustard, and mayo as desired. Serve immediately and enjoy your juicy, flavor-packed Crack Burgers!