Start by grabbing a large mixing bowl. Combine the ground beef, barbecue sauce, Worcestershire sauce, garlic powder, black pepper, and salt. Using your hands, get in there and mix everything together until just combined. It’s best if you don’t overwork the meat to keep those patties tender.

Now comes the fun part! Scoop out a handful of the beef mixture—about ¼ pound—and form it into flat patties. You’ll want to make about 12 of these. Place them on a cookie sheet lined with plastic wrap, ensuring they're not touching. Cover them up and let them chill in the refrigerator for about 20 minutes. This helps them hold together better when cooking.

While those patties are chilling, it’s time for bacon! Heat a large skillet over medium-high heat, then toss in the chopped bacon. Cook until the pieces are crispy and browned, which should take around five minutes. Use a slotted spoon to remove the bacon and set it aside on paper towels to drain off the excess grease. In the same skillet, reduce the heat to medium, add the diced onions to the bacon drippings, and sauté until soft and starting to caramelize, about five minutes. Combine the bacon and onions in a bowl for the filling later.

Fire up your outdoor grill, setting it to medium heat while you prepare to fill those patties. Lightly oil the grill grate to prevent the burgers from sticking, ensuring a smooth cooking process.

Once the patties have chilled, take out those six patties from the cookie sheet to start the assembly. For each of these, apply roughly 1½ tablespoons of the bacon-onion mixture and then sprinkle shredded cheese on top. Grab a second patty and place it atop the stuffed one. Carefully press the edges together to seal in that delicious stuffing; you don't want it leaking out while grilling.

Now for the grilling! Place the filled patties on the preheated grill. Allow them to cook for about 4 to 5 minutes on each side. Keep an eye on them; you want the internal temperature to reach at least 160 degrees F (70 degrees C). A meat thermometer will be your best friend here.

Once those patties are cooked through, take them off the grill. Place them on hamburger buns and serve with your favorite condiments—think ketchup, mustard, or even a little extra barbecue sauce. Your filled burgers are ready to be devoured!