BBQ Bacon Smash Burger with Bacon-Onion Barbecue Sauce

A comfort-food burger that still feels like an upgrade

Cheeseburgers are hard to beat, but even the most loyal burger fans sometimes want something beyond the standard patty-and-cheese routine. Bacon is often the first upgrade people reach for, yet there’s another approach that can make a familiar burger feel new again: build the bacon into the sauce instead of simply laying strips on top.

This BBQ bacon smash burger does exactly that. It keeps the classic comforts—thin patties, melted American cheese, toasted buns—while adding a “next level” bacon-onion barbecue sauce that leans smoky, tangy, and sweet. The bacon contributes savoriness, the onions bring a caramelized sweetness, and the overall effect is an elevated burger that still tastes like something you’d gladly eat with fries on a casual night in.

Another practical bonus: the sauce recipe can yield leftovers. That means you can be generous when you dress the burgers, then keep the remaining sauce for dipping tater tots or fries. Just remember it should be refrigerated and, because it contains added protein (bacon), it will have a slightly shorter shelf life than many homemade barbecue sauces—about a week in a sealed container.

What makes this burger different: bacon inside the barbecue sauce

Many bacon burgers rely on crispy strips stacked over the patty. Here, the bacon is diced, cooked until crisp, and then returned to a simmering barbecue sauce built on ketchup, mustard, brown sugar, vinegar, and a few deeply savory seasonings. The onions cook directly in the bacon drippings before the rest of the sauce ingredients go in, which helps the onion soften and lightly brown while picking up the smoky richness left behind in the pan.

The finished sauce is designed to be used generously. It’s tangy and smoky, with sweetness from the onions and brown sugar and additional depth from ingredients like soy sauce and Worcestershire sauce. Because the bacon is folded into the sauce, every bite of burger can carry that smoky-sweet combination—without needing a separate layer of bacon on top.

Ingredients you’ll need

This recipe has two main components: the bacon-onion barbecue sauce and the smash burgers themselves. Gather everything first so you can move smoothly from sauce to patties while the pan and griddle are hot.

Bacon-onion barbecue sauce

• Bacon (diced)
• Yellow onion
• Ketchup
• Dijon mustard
• Brown sugar
• Apple cider vinegar
• Soy sauce
• Worcestershire sauce
• Onion powder
• Garlic powder
• Smoked paprika

Smash burgers and assembly

• Ground beef
• Mayonnaise
• Salt
• Pepper
• Burger buns
• Salted butter (softened, for toasting buns)
• American cheese
• Scallion (for garnish)
• Pickles (for topping)

Step-by-step: make the bacon-onion barbecue sauce

The sauce is cooked in a saucepan and starts with bacon, which provides both flavor and the drippings used to sauté the onion.

• Cook the diced bacon over medium heat until brown and crisp.
• Remove the cooked bacon from the saucepan using a slotted spoon and set it aside. Keep the bacon drippings in the pan.
• Add the onions to the pan, stir to combine with the bacon drippings, and sauté until soft and lightly brown, about 5 minutes.
• Add ketchup, Dijon mustard, brown sugar, apple cider vinegar, soy sauce, Worcestershire sauce, onion powder, garlic powder, and smoked paprika. Whisk to combine and bring to a simmer.
• Once simmering, reduce the heat to low, return the bacon to the pan, and continue to cook for 10 minutes, stirring frequently.

When it’s done, the sauce should be cohesive and spoonable, with bacon distributed throughout. If you’re not using it immediately, refrigerate it in a sealed container. Because of the added bacon, plan to use leftovers within about a week.

Step-by-step: prep the burger mixture

These are smash burgers, which means the patties are pressed thin on a hot surface to maximize sear and crispness. The mixture itself is simple—ground beef seasoned with salt and pepper—plus one less-common addition: mayonnaise.

• Place the ground beef, mayonnaise, salt, and pepper in a large bowl.
• Using your hands, mix until thoroughly combined.
• Divide the burger mixture into 8 even balls.

Those eight balls become thin patties once smashed on the griddle. The final burger build uses two patties per bun, stacked for a classic double-smash-burger feel.

Toast the buns

Toasting the buns adds texture and helps them stand up to a generous amount of sauce.

• Spread the buns with softened salted butter and toast until lightly golden. Set aside.

Smash-burger technique: how to get thin patties with a deep sear

Smash burgers are defined by their thinness and the crisp, caramelized exterior that comes from strong contact with a hot cooking surface. The key is pressure. The patties are pressed down firmly so they don’t shrink inward and thicken as they cook.

Constant weight matters because it helps create maximum sear. A burger press works, but a slightly smaller heavy-bottom skillet can also do the job. The goal is to keep the meat in full contact with the pan so the outside browns deeply and evenly.

There’s another important detail: pressing once and then releasing can allow thin patties to pucker or bubble. When that happens, the surface loses contact with the hot pan, and you lose sear—exactly what you don’t want. Reapplying the press after flipping helps maintain that contact and builds the crisp exterior on both sides.

Step-by-step: cook the smash burgers

Work in batches if needed so the pan stays hot and the patties have room. A large skillet or griddle pan is ideal.

• Spritz a large skillet or griddle pan with cooking spray and preheat over medium-high heat.
• Once hot, working in batches if necessary, add the burger balls to the skillet, and sear for 1 minute.
• Firmly press the burgers flat using either a burger press or a slightly smaller heavy-bottom skillet.
• Cook for 2 minutes or until deeply seared.
• Flip the burgers, reapply the press, and sear for another 2 minutes on the other side until deeply seared.
• Remove the press and top burgers with American cheese slices (1 slice per burger).

Once the cheese has melted, the patties are ready to stack and assemble. Because these are thin patties, the double stack helps deliver a satisfying bite while keeping the signature smash-burger crispness.

Build the burgers

Assembly is straightforward, but the order matters: toasted bun, stacked patties, lots of sauce, then fresh toppings for contrast.

• Once the cheese has melted, stack 2 burgers on a toasted bottom bun.
• Generously top the burgers with the bacon-onion BBQ sauce.
• Garnish the sauced burgers with scallions and pickle slices.
• Cap with the toasted top bun and serve.

The scallions add a fresh bite, and the pickles bring acidity and crunch—both useful counterpoints to the rich beef, melted American cheese, and smoky-sweet sauce.

Why mayonnaise belongs in the patty mix

Mayonnaise may not be the most typical ingredient in a burger patty mixture, but it serves multiple purposes here. First, it supports caramelization. Similar to using mayonnaise on the outside of grilled cheese instead of butter, mayo can help create a more uniform, crispy brown crust and a faster-forming crust—an advantage when you’re trying to build a strong sear on a very thin patty.

Second, it helps with moisture retention. Thin patties can release moisture faster than thicker ones, especially when pressed. Mayo’s oil/fat-based ingredients help maintain and enhance juiciness, even as the patty cooks quickly on a hot surface.

Third, it adds flavor. Mayo contributes savory depth and a subtle tangy richness that complements beef. If you prefer to omit the mayo, you can do so, but the guidance here is to choose higher-fat ground beef—an 80/20 or 85/15 ratio—and avoid lean beef, which can dry out more easily in thin patties.

Serving ideas and storing leftover sauce

This burger is designed to be saucy, and that’s part of the appeal. If you end up with extra bacon-onion barbecue sauce, it’s worth saving specifically for dipping. Fries and tater tots are natural pairings, especially because the sauce carries both sweetness and tang.

Store leftover sauce in the refrigerator in a sealed container. Because it contains bacon, it won’t last as long as many other homemade barbecue sauces; plan to use it within about a week.

The takeaway

Thin, crispy patties. Melted American cheese. A tangy, smoky-sweet barbecue sauce that’s enriched with bacon and onions cooked in bacon drippings. This BBQ bacon smash burger keeps the familiar pleasures of a classic cheeseburger while adding a distinctive sauce that makes the whole build feel special. It’s a straightforward method with a clear payoff: maximum sear on the patties, a rich sauce you can spoon on generously, and a burger that lands firmly in comfort-food territory—just with a little extra edge.