In a large bowl, mix the ground beef, salt, black pepper, garlic powder, and onion powder until well combined. Divide the mixture into 4 equal portions and shape them into patties. Set aside.

Cook the bacon in a large skillet over medium heat until crispy. Remove the bacon from the skillet and drain on a paper towel-lined plate. Set aside.

In a shallow dish, whisk together the flour and paprika. Pour the buttermilk into another shallow dish.

Dip each onion ring into the buttermilk, then coat it with the seasoned flour mixture. Repeat the process until all onion rings are coated.

Heat vegetable oil in a large skillet or deep fryer to 375°F. Fry the coated onion rings in batches until golden brown, about 2-3 minutes per side. Remove the onion rings from the oil and drain on a wire rack or paper towel-lined plate.

Preheat a grill or cast-iron skillet over medium-high heat. Cook the burger patties for about 4-5 minutes on each side, or until they reach the desired level of doneness. During the last minute of cooking, place a slice of cheddar cheese on each patty.

Assemble the burgers by spreading BBQ sauce on the bottom half of each toasted bun. Place a cheese-topped patty on the sauce, followed by 2 slices of bacon and 2-3 fried onion rings. Add any optional toppings, such as lettuce, tomato, pickles, or mayonnaise.

Place the top half of the bun on the burger and serve immediately.