- In a small bowl, stir together the salt, pepper, garlic powder, onion powder, and paprika.
- Preheat your flat-top grill/pan to medium. Cook the bacon until crispy, 8-10 minutes. Place on a paper towel-lined plate.
- Add the butter to the grill/pan and let it melt.
- Add the onions and toss to coat in the butter. Season with about 1/4 of the seasoning mixture. Toss with a spatula frequently until they wilt and begin yo brown, about 8-10 minutes. Take off the heat.
- Turn up the heat to high and grease the grill/pan with oil.
- Season the burger patties with some of the seasoning mixture on the top.
- Place the patties seasoning side down on the grill/pan.
- Using a piece of parchment paper and a spatula, smash each burger patty down as thin as you can, concentrating on the edges.
- Season this side after smashing. Allow to cook until the meat looks lacey and browns around the edges, about 2 minutes.
- Flip the patty over. Brush this side with BBQ sauce. Immediately add a slice of cheese. Continue to cook until the cheese melts, about 2 minutes.
- Take them off the grill/pan and serve with your favorite toppings!