Prepare the onion rings by preparing the batter and slicing the onions. Heat oil to 350°F (175°C). Fry onion slices until golden brown and crispy, about 2-3 minutes per side. Set aside.

In a frying pan, cook the bacon strips over medium-high heat until crispy, about 6-8 minutes. Transfer to a paper towel-lined plate and reserve about 2 tablespoons of grease.

Combine the ground beef with salt, black pepper, and paprika. Divide into 12 portions and roll into balls.

Heat the pan with the reserved bacon grease. Place 2-3 beef balls and smash down to about ¼ inch thick. Cook for about 2 minutes until crust forms.

Flip the patties, press down again, and cook for an additional minute. Top each with 1 slice of cheese, cover to melt.

Stack two patties on each burger bun.

Spread mayo on the bottom bun, add the cheesy patties, crispy bacon, 2-3 onion rings, drizzle BBQ sauce, and finish with the top bun.