Recreate the legendary In-N-Out 4x4 burger at home with this recipe, featuring four juicy patties, four slices of cheese, and that iconic secret sauce. This dish captures the essence of the beloved fast-food classic.
Prepare the "Spread": In a small bowl, combine mayonnaise, ketchup, sweet pickle relish, white vinegar, sugar, salt, and pepper. Mix well and set aside.
Prepare the toppings: Finely shred the iceberg lettuce. Thinly slice the tomato and white onion. Set aside.
Form the patties: Divide the ground beef into four equal portions (approximately 4 oz or 115g each). Form each portion into a very thin patty, slightly wider than your burger bun, as they will shrink significantly. Season both sides of each patty generously with salt and black pepper.
Toast the bun: Heat a large cast-iron skillet or griddle over medium heat. Lightly butter or oil the cut sides of the burger bun and toast until golden brown, about 1-2 minutes. Remove and set aside.
Cook the patties: Increase the heat to medium-high. Add 1 tbsp of oil or butter to the skillet. Place two of the seasoned patties in the hot skillet. Press down firmly with a spatula for 30 seconds to create a good crust (smash burger style). Cook for 1-2 minutes per side for medium-well, or until desired doneness. During the last 30 seconds of cooking, place one slice of American cheese on each patty to melt.
Repeat with remaining patties: Remove the first two cooked patties with melted cheese and set aside. Repeat the cooking process with the remaining two patties, topping each with a slice of American cheese to melt.
Assemble the 4x4: Spread a generous amount of the "Spread" on both the top and bottom halves of the toasted bun. Layer the bottom bun with shredded lettuce, tomato, and onion slices. Stack the four cheeseburger patties on top of the vegetables. Add any extra desired toppings or sauce, then place the top bun to complete your Homemade In-N-Out Style Quad Burger.
Serve immediately and enjoy your epic burger!