Preheat your Yoder Smokers YS640s Pellet Grill to 450ºF, set up for direct grilling (diffuser plate removed), and a Yoder Smokers Reversible Cast Iron Griddle in place over the fire box, smooth side up.
Form your ground beef into 12 (2 oz) balls. Refrigerate until ready to grill.
To make the sauce, combine the Duke’s mayonnaise and Kozlik’s Dijon Classique Mustard and mix well.
Cook the bacon on the griddle to desired doneness. Remove from the grill and drain on paper towels.
Place the thin sliced onions on the griddle. Season with Meat Church Honey Bacon BBQ Rub. Toss the onions with a spatula to coat in seasoning and bacon grease. Spread out into an even layer. Cook, scraping and turning with the spatula occasionally to cook evenly. Remove the onions from the griddle when they are softened and beginning to brown, about 10 minutes.
Load your Cattleman’s Grill Trail Dust All Purpose Seasoning into a spice grinder set for a fine grind.
Place your balls of ground beef on the griddle in rows of three. Stopping to smash the beef with a large firm spatula after placing on the grill. Smash each patty to a width slightly larger than the diameter of your buns, as the patties will shrink considerably while cooking. Then season the meat with the Cattleman’s Grill Trail Dust All Purpose Seasoning. Work in rows of three repeating this process.
When the bottoms of the patties are dark brown and seared, flip and season again with Cattleman’s Grill Trail Dust All Purpose Seasoning. Place a half slice of cheese on top of each patty, then lay two half slices of bacon in an X shape over the cheese. Place the top half of the Hawaiian roll on the bacon, and the bottom half on top of the top bun. This allows the rolls to steam and warm as the burger finishes cooking.
When the bottoms of the burgers are seared and the cheese is melted, remove from the griddle.
Spread the mayo/mustard sauce on the bottom bun, then top with the grilled onions. Place the burger patty, bacon and top bun over the onions.