Ninja smash burgers are a griddle-cooked smash burger built for an outdoor grill setup. Two pounds of ground beef divided into four meatballs, smashed aggressively thin on a hot oiled griddle or cast iron pan, double-stacked with American cheese, grilled onions, sriracha mayo, and arugula on toasted potato buns. The method produces the thin, lacy-edged patty with a deeply caramelized crust that's the whole point of a smash burger.

The smash technique works by maximizing contact between the beef and the hot surface. A round meatball has minimal surface area touching the griddle; pressing it flat increases the contact dramatically and produces the Maillard browning across the entire patty face that a thick burger achieves only on a thin band around the sear line. The crust is the flavor, and smashing creates more crust per bite than any other burger method.

The beef and the seasoning

Two pounds of ground beef divided into four equal meatballs, about half a pound each. The recipe uses a seasoning blend of salt, pepper, and dried chiles; a straightforward substitute is coarse salt, cracked black pepper, and a pinch of cayenne or ancho chili powder. Season the meatballs before they go on the griddle rather than after smashing; the seasoning needs to be on the exterior surface that will contact the heat.

Ground beef with higher fat content, eighty percent lean, produces a more flavorful crust and stays moist through the aggressive smash. Leaner ground beef dries out more quickly and produces a less juicy finished burger. This is not a recipe where lean ground beef is the right choice.

The griddle setup and onions

Preheat the grill to medium, direct heat with a large griddle or cast iron pan sitting on the grates. Grill the thinly sliced white onion until softened and slightly charred, about three minutes. Toast the potato buns cut-side down on the griddle at the same time. Both can happen while the griddle preheats and before the burgers go on. The onions and buns should be done and set aside before the beef hits the pan.

When to smash and when to flip

Lightly oil the griddle and place the meatballs on the surface with space between them. Watch for juices pooling at the bottom of each meatball against the griddle surface. That pooling is the signal that the beef has heated through enough that its fat has started to render; this is the moment to smash. Use a burger press or a large heavy metal spatula pressed firmly and held for a few seconds until the patty is spread very thin. The smash should happen once and decisively; going back to re-smash after the crust has started to set tears the crust.

After smashing, watch for juices pooling on the top surface of the patty. This is the flip signal. The patty is cooking from the bottom up; once juice appears on the top the interior heat has risen enough that flipping won't result in the patty sticking or tearing. Flip once, add two slices of American cheese per patty, and cook until the cheese is melted. American cheese melts evenly and quickly at griddle temperature; it's the right cheese for this format.

Building the burger

Sriracha mayo on the bottom bun, a pinch of baby arugula, one patty with melted cheese, a layer of grilled onions, a second patty, and more onions. The double-patty stack is the format that makes a smash burger substantial given how thin each individual patty is. A single smash patty is a thin disc of beef; two together produce a burger with enough structural presence to eat as a meal.

The sriracha mayo provides the creamy, spicy element that holds the arugula in place and adds richness to the lean-tasting arugula. The arugula adds a peppery bite that cuts through the richness of the double patty and the cheese. The potato bun is the right bun for this: slightly sweet, soft, and able to absorb the rendered beef fat without disintegrating. Serves 4. No nutrition data was provided for this recipe.

Indoor adaptation

This works equally well on a flat griddle or cast iron pan on a stovetop burner over medium-high heat. The outdoor grill setup adds a slight smoky character but is not essential to the technique. A well-seasoned cast iron skillet on a high-BTU burner produces a crust comparable to the griddle version. Work in two batches on a standard home stovetop pan to avoid crowding.