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

In a bowl, mix mayonnaise, chopped bacon, Dijon mustard, garlic powder, onion powder, and a pinch of salt and pepper to prepare the baconnaise sauce.

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

Place the beef balls on the hot skillet and immediately smash them down with a spatula to form thin patties. Cook for about 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 melted.

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

Assemble the burgers by spreading a generous amount of baconnaise sauce on the bottom half of each bun. Place a burger patty on top, then add any additional toppings desired, and cover with the other half of the bun.