In-N-Out Double-Double Animal Style (Copycat Recipe)

This copycat makes two Double-Double-style burgers with four thin, mustard-fried beef patties, melted American cheese, browned onions, pickles, lettuce, and a tangy spread. Cook the onions first, then sear the patties in a hot skillet and check that the beef reaches 160°F (71°C). A toasted soft bun brings the layers together.

A griddle-style burger can feel like a treat that takes more planning than it does. The key is to cook the onions while you prep the other ingredients, then work quickly when the thin patties hit the pan. I use this order to keep the meat hot, the cheese melted, and cleanup manageable.

This is a home copycat, not an official restaurant recipe. The patty size and spread below are practical choices for a home stove. You can use cast iron, carbon steel, or suitable stainless steel; the method also works with PTFE nonstick when you follow the pan maker’s heat limits.

Material Setup and Ingredient Prep

This recipe makes two burgers, each with two patties. Set out all the toppings before cooking, and keep raw beef tools and plates away from ready-to-eat food. A little prep makes the fast griddle steps easier to manage.

Ingredients

• 1 medium onion, thinly sliced
• 1 tablespoon butter or neutral oil, plus a little more for the buns if needed
• 3 tablespoons mayonnaise
• 1 tablespoon ketchup
• 1 tablespoon sweet pickle relish
• 8 ounces (227 g) ground beef, divided into four balls of about 2 ounces (57 g) each
• Kosher salt and black pepper
• 4 teaspoons yellow mustard
• 4 slices American cheese
• 4 soft burger buns
• Dill pickle slices
• Lettuce leaves

The spread combines familiar burger-sauce flavors. Stir the mayonnaise, ketchup, and relish together in a small bowl. Taste it, then add a little more relish for sweetness or ketchup for tang. This is a flexible home version, not a claim about the restaurant’s exact formula.

Slice the onion thinly so it softens at a steady pace. Keep the beef cold until you are ready to cook. Shape it into loose balls rather than firm, smooth patties; you will press each portion thin on the hot cooking surface.

Choose a Pan That Suits Your Stove

Cast iron and carbon steel hold heat well and work on gas or induction. Stainless steel is also suitable if its base is induction-compatible when needed. PTFE nonstick can work, but check its maker’s heat limit and avoid heating it empty.

For uncoated metal cookware, preheat over medium-high heat for 3 to 5 minutes. Aim for a cooking surface around 375–400°F (191–204°C), if you have an infrared thermometer. If you use PTFE nonstick, do not chase that surface temperature if it exceeds the pan’s rating. Follow its instructions instead.

Onion, Mustard-Fried Patty, and Assembly Technique

Mustard-frying means spreading yellow mustard on the exposed side of a patty, then turning that side onto the hot pan. The mustard cooks against the surface as the beef sears. Cook onions first, toast the buns, and save the hot pan for the patties.

Cook the Onions

1. Heat the butter or oil in your skillet over medium to medium-low heat.
2. Add the sliced onion and stir to coat.
3. Cook for 15 to 20 minutes, stirring now and then, until the onion is very soft and deeply browned.
4. If it sticks before it softens, add a small splash of water and stir. Do not add a large pour; you want the onions to brown, not simmer.
5. Transfer the onions to a clean bowl.

Onions take longer than the patties, so give them the first turn on the stove. Once they are done, use the same pan to toast the buns. Place the buns cut-side down and toast until golden, then set them aside.

Cook the Thin Patties

Make sure the pan is hot before adding the beef. Set one beef ball on the surface and press it into a thin patty with a sturdy spatula. Keep the portions separate, and work in batches if the pan feels crowded. Season the exposed side with salt and pepper.

Spread about 1 teaspoon of yellow mustard over each patty’s exposed side. When the first side is browned and releases from the pan, flip the patty so the mustard side meets the cooking surface. If it resists, give it a little more time rather than scraping it loose. A thin metal spatula works on uncoated metal pans, but do not use it on PTFE-coated cookware.

Cook the patties through, then check the center of one with a food thermometer. Ground beef should reach 160°F (71°C), in line with USDA consumer guidance. Thin patties cook quickly, but a browned crust alone does not confirm a safe internal temperature. Top each cooked patty with a slice of American cheese and let it melt.

Build Each Burger

Spread sauce on the cut sides of the toasted bun. Add pickles and lettuce to the bottom half, then stack two cheese-topped patties and some browned onion. Cap with the top bun and serve while the patties are hot.

You can change the order if you prefer. Putting onions directly on the cheese keeps them in the warm center; putting pickles below the patties gives their sharp flavor a clear bite. Keep the two patties stacked so each burger has the double-layered shape and texture.

Cookware Cleaning and Seasoning Care

Let the pan cool until it is safely warm before cleaning. Do not pour cold water onto a hot pan: a sudden temperature change can damage cookware. Cleaning depends on the surface, so follow the pan maker’s directions, especially for coated pans.

For cast iron or carbon steel, wipe away grease and food bits, then wash as needed with warm water and a brush or sponge. Dry the pan promptly and fully. For bare cast iron or carbon steel, a thin film of cooking oil can help protect the surface; avoid leaving a thick, sticky layer.

Wash stainless steel according to its care instructions. For PTFE nonstick, use a soft sponge and avoid metal utensils or abrasive tools that could damage the coating. Do not use aerosol cooking spray on PTFE nonstick, as residue can build up. Never preheat a coated pan empty.

Raw beef safety matters during cleanup, too. Wash your hands after handling raw meat, and clean the plate, spatula, and work surface that touched it before using them for cooked food. Do not put cooked patties back on a plate that held raw beef.

Serving, Stacking, and Stovetop Scenarios

Serve the burgers right after assembly so the cheese stays soft and the buns stay warm. The recipe makes two burgers from four patties. If you are cooking for more people, keep the browned onions and toasted buns ready, then cook the beef in batches rather than crowding the skillet.

A standard home stove may heat unevenly, especially under a wide skillet. If the patties brown much faster on one side, rotate the pan or cook in smaller batches. Give the pan time to recover between batches, and check each batch for the safe internal temperature.

These two common setups show how to adjust without changing the core method:

If your kitchen has only one skillet, the sequence still works: onions, buns, then patties. If you have a separate griddle or second pan, you can toast buns while the onions finish, but it is not required. A thermometer is more useful than guessing from color, particularly with thin patties.

Frequently Asked Questions

These answers cover the main choices that affect the burger’s texture, timing, and safety. The quantities and cooking steps refer to this two-burger home recipe, and the beef temperature follows USDA consumer guidance.

How many patties does this recipe make?
It makes four patties, about 2 ounces (57 g) each. Stack two patties in each of two burgers.

Does the restaurant use this exact recipe?
No. This is a home copycat with practical portions and a simple spread. It is not an official recipe.

What does mustard-fried mean?
It means adding yellow mustard to the exposed side of the patty, then flipping that side down onto the hot pan.

What temperature should ground beef reach?
Cook ground beef to 160°F (71°C) in the center. Check with a food thermometer rather than judging by color alone.

Can I use a nonstick pan?
Yes, if the pan maker allows this type of cooking. Follow its heat limit, do not preheat it empty, and avoid aerosol cooking spray.

How long do the onions take?
Plan on 15 to 20 minutes over medium to medium-low heat. Stir now and then, and add a small splash of water if they stick before becoming tender.

Why is my patty sticking to the pan?
It may need more time to brown and release. Wait briefly before turning, then slide a spatula under it. Do not use a metal spatula on PTFE nonstick.

Can I make the spread ahead?
Yes. Mix the mayonnaise, ketchup, and relish before cooking, cover it, and keep it chilled until you assemble the burgers.

Can I cook all four patties at once?
Only if they fit without crowding and the pan stays hot. Otherwise, cook in batches for more even browning.

What can I use instead of American cheese?
Use another cheese that melts well, though the flavor and texture will differ. Add it after the patties reach a safe temperature so it can melt from the residual heat.

For the most reliable result, cook the onions slowly, let the patties release before turning, and confirm the beef reaches 160°F (71°C). These small checks make the stovetop method easier to repeat.

(This article was written by one of our staff writers, Steven R. Bancroft. Visit our Meet the Team page.)