Disclosure: This post may contain affiliate links, which means I may earn a commission if you click on the link and make a purchase. Ingredients You’ll Need for In-N-Out Burger Copycat 80/20 Ground beef – The fat ratio is key. It creates juiciness and encourages browning, which gives you that signature crust when pressed into a hot skillet. American cheese – This melts smoothly and evenly over the thin patty, creating that classic creamy layer. Yellow onions – Slowly caramelized, they add sweetness and depth that balance the savory beef and tangy sauce. Burger sauce – The pickles bring acidity and crunch, while mayonnaise forms the creamy base. Together with ketchup and Dijon, they create a balanced, slightly tangy burger sauce. Iceberg lettuce and vine-ripe tomatoes – Iceberg provides crisp texture, and thick slices of tomato add freshness to contrast the rich patty and cheese. Burger buns – Pillowy soft, classic white bread is my go-to, but a potato bun works well here, too. For the rest of the ingredients, please refer to the recipe index card below! How to Make In-N-Out Burger Copycat Caramelize the onions. Cook onions on medium heat for about 30 minutes, until the onions are deep brown. Set aside. Make the burger sauce. In a small bowl, mix minced dill pickles, mayonnaise, ketchup, Dijon mustard, garlic powder, salt, and black pepper. Refrigerate until ready to use. Form the beef. Divide the ground beef into 2-ounce balls. Season with salt and black pepper. Toast the buns. Butter the cut sides of the buns and toast them in a cast-iron skillet. Smash and sear. Heat the skillet until very hot. Lightly coat with oil, add the beef balls, and immediately press each into a thin patty using a meat press or sturdy spatula. Cook for 1 minute, until the edges are deeply browned and crisp. Flip, top with American cheese, and cook for another minute until melted. Assemble. Spread burger sauce on the bottom bun. Layer with tomato, lettuce, the cheesy patty, caramelized onions, another patty, and more onions. Add more sauce to the top bun, close, and enjoy! Quick Tips for the Best In-N-Out Burger Copycat Use a cast-iron skillet or flat top. I find this the best way to get that Maillard reaction (the beautiful brown crust on the meat). Make it spicy. Add some chopped chilis and a drizzle of the brine. So good! Go protein style. Eliminate the burger bun and build your burger between two hunks of iceberg lettuce. It’s honestly so good this way, kind of like a burger salad. Make-Ahead, Storage & Reheating This recipe is best made fresh, but here are a few things you can prep ahead: The burger sauce can be made up to 3 days in advance and stored in an airtight container in the refrigerator. Caramelized onions can be cooked ahead and refrigerated; rewarm gently before assembling. Portion and shape the beef into loose balls, then wrap tightly and refrigerate until ready to cook.