Mix the ground beef, bread crumbs, onion, egg, garlic powder, 1 cup barbecue sauce, and salt and pepper together.
Form the mixture into 6 burger patties. Chill in the fridge until ready to cook.
Preheat your grill or skillet to medium-high heat. Add the burgers to the grill and cook for 6-7 minutes.
Brush the burgers with barbecue sauce. Then, flip and cook for another 5 minutes.
When the burgers are just about done cooking, add sliced cheese on top of the burgers.
At this time, also add the pretzel buns cut-side-down onto the grill and allow them to get toasty.
Then, remove the buns from the grill and place the burgers onto the buns.
Serve with extra barbecue sauce and a handful of crispy fried onions on top.