Viral In-N-Out Double-Double Smash Burger

This is the burger that broke the internet: a double-double smash burger with two thin, craggy-edged patties, molten American cheese, sweet caramelized onions, and a tangy secret-style spread.

The method is pure technique—smashing beef onto a screaming-hot griddle to create maximum crust, then stacking it high on a butter-toasted bun. Every bite delivers a crackle, a drip, and a burst of savory flavor. Best of all, it comes together in about 30 minutes, making it the ultimate weeknight indulgence for burger lovers.

The In-N-Out Double-Double is a West Coast icon, but this version brings the experience home with a few simple tricks. Two smashed patties are cooked until their edges are lacy and caramelized, then topped with cheese that melts into every crevice.

The signature spread—a creamy, tangy blend of mayo, ketchup, and relish—ties everything together. With fresh lettuce, tomato, pickles, and those slow-cooked onions, each layer has a purpose. This recipe is designed for home cooks who want that drive-thru magic without leaving the kitchen.

Ingredients

Why this recipe works

Smashing the beef into thin patties maximizes surface area, which means more browning and more flavor. The Maillard reaction creates hundreds of tiny crispy bits that cling to the meat, giving each bite a satisfying crunch.

Using 80/20 ground beef ensures enough fat to keep the patties juicy even when cooked to well-done, as smash burgers traditionally are. The high heat of the griddle is essential—it sears the meat quickly, locking in juices and building that iconic crust.

The spread is more than just a condiment; it's the glue that holds the burger together. The combination of creamy mayonnaise, tangy ketchup, and sweet relish mimics the classic thousand-island style that In-N-Out is famous for.

A touch of vinegar brightens the sauce, cutting through the richness of the beef and cheese. Toasting the buns in butter adds a nutty flavor and a crisp texture that prevents sogginess, ensuring every layer stays distinct and delicious.

Notes and substitutions

For the best results, use 80/20 ground beef—the higher fat content is what gives smash burgers their juicy, tender texture. If you can only find leaner beef, add a tablespoon of butter to each patty before cooking to compensate. The spread can be made ahead and refrigerated for up to a week; just stir it well before using. American cheese is the classic choice because it melts smoothly, but cheddar or provolone also work if you prefer a sharper flavor.

A flat-top griddle is ideal for smashing multiple patties at once, but a large cast-iron skillet works just as well. Make sure the pan is thoroughly preheated before adding the beef—you want a sizzle the moment the meat touches the surface. Use a stiff metal spatula to press down firmly; a thin spatula will make it easier to scrape under the crust when flipping. If you don't have a burger press, the bottom of a heavy skillet can be used to flatten the patties.

• American cheese: Sharp cheddar or provolone slices, if preferred
• 80/20 ground beef: Ground chuck (85/15) works, but patties will be slightly less juicy
• Sweet pickle relish: Finely chopped bread-and-butter pickles
• Burger buns: Potato rolls or brioche buns, toasted

Equipment

• Flat-top griddle or large cast-iron skillet
• Metal spatula
• Bench scraper
• Mixing bowl
• Whisk
• Basting brush