Preheat a cast-iron skillet or griddle over medium-high heat.

In a bowl, prepare the baconnaise sauce by mixing together mayonnaise, chopped bacon, Dijon mustard, garlic powder, onion powder, and a pinch of salt and pepper. Set aside.

Divide the ground beef into 4 equal portions (about 4 ounces each). Form each portion into a loose ball without compacting it too much. Season with salt and pepper.

Once the skillet is hot, place the beef balls on the skillet and smash them down with a spatula to form thin patties. Cook for 2-3 minutes until the edges are crispy and browned.

Flip the patties, add a slice of cheese to each, and cook for an additional 1-2 minutes until the cheese is beautifully melted.

Spread butter on the insides of the hamburger buns and toast them in a separate skillet until golden brown.

Assemble the burgers by spreading a generous amount of baconnaise sauce on the bottom half of each bun. Top with a burger patty, and add any additional toppings you desire. Finish with the top half of the bun and serve immediately.