The BBQ bacon burger is defined by a sauce that does a job no condiment on a plain cheeseburger is asked to do: it has to survive being layered against bacon, smoked-paprika sweetness fighting smoked-pork salt, and still register as its own flavor on the way down. Barbecue sauce on a burger is not ketchup with extra notes. It is thick, tomato-sweet, vinegar-sharp, and applied with the understanding that it will be the loudest thing in the build. That decision, sweet sauce as the headline rather than the accent, is the whole sandwich. The patty, the bacon, the bun, and the rings all answer to it.
The craft is about managing fat against fat without the thing collapsing into one greasy note. A griddled or flame-cooked beef patty already renders heavily; bacon adds a second rendered-pork load on top of it; the barbecue sauce is the only sweet, acidic counter holding the two apart. The bacon is cooked crisp rather than chewy on purpose, because a flexible strip slides out of the build and a brittle one snaps clean under the bite and reads as texture against a soft patty. Onion rings, when they go on, are structural as much as they are flavor: a battered, fried ring is a second crisp element and a height-builder, and it has to be drained hard so it does not steam soft against the hot patty and the wet sauce. The bun is sized to take that much sauce and grease, soft enough to compress to the stack and sturdy enough that the bottom does not blow out before the last bite. Cheddar is the usual cheese here rather than American, picked because its sharpness has a chance of being heard under the sauce.
The variations move the sweet-and-smoke lever in predictable directions. A version that swaps the rings for fried jalapenos trades the height for heat. A pulled-pork-topped build doubles down on the barbecue idea and pushes the burger toward its smoked-meat cousins. A cheddar-and-bacon build with no sauce at all is a different sandwich entirely and belongs with the plain bacon cheeseburger. Each of those carries its own rules and deserves a proper article rather than being crowded in here.