Make the Big Mac sauce

• Mix the mayonnaise, ketchup, mustard, relish, vinegar, paprika, garlic powder and onion powder in a bowl.
• Season with salt and pepper and chill until serving.

Prepare the toppings

• Shred the lettuce and dice the onion.
• Slice the pickles and the cheese.

Shape the patties

• Divide the ground beef into thin patties and season both sides with salt and pepper.

Toast the buns

• Brush the bun layers with melted butter.
• Toast them in a hot pan until golden, then set aside.

Cook the patties

• Sear the patties in the hot pan until browned and cooked through.
• Top each patty with a slice of cheese and let it melt.

Assemble the burgers

• Spread sauce on the bottom bun, add lettuce, a patty with cheese, pickles and onion.
• Add the middle bun layer with more sauce, then lettuce, the second patty, pickles and onion.
• Close with the top bun and serve immediately.