Divide the 1 lb ground beef into 4 equal portions (about 4 oz each). Gently form each portion into a loose ball without overworking; do not compress. Refrigerate while you prepare the griddle and other components for 10 minutes to firm slightly.

Preheat griddle

Heat a cast-iron griddle or heavy skillet over medium-high heat until very hot (about 5–7 minutes). Add 1 tablespoon vegetable oil and spread to coat.

Smash technique

Place one beef ball on the hot griddle. Using a sturdy spatula or a heavy-duty burger press lined with parchment, press down firmly until patty is about 1/4 inch thick, edges ragged. Season immediately with a pinch of kosher salt and a light sprinkle of black pepper. Repeat for remaining patties, working in batches; do not overcrowd.

Sear and flip

Cook smashed patties without moving for 2–3 minutes until deep brown and crisp at the edges. Flip and cook an additional 45–60 seconds. Add 1/2 tablespoon softened butter to each patty after flipping to help finish and add flavor.

Add cheese

Place a slice of American cheese on each patty immediately after flipping and allow it to melt for 30–45 seconds while finishing on the heat. Remove patties from the griddle and keep warm on a plate tented with foil.

Buns & Assembly

Toast buns

Slice potato buns and butter cut sides lightly with the remaining softened butter. Toast cut sides on the hot griddle for about 30–45 seconds until golden and slightly crisp. Remove and keep warm.

Assemble burgers

Spread about 1 tablespoon of Classic Burger Sauce on the bottom half of each toasted bun. Add shredded iceberg lettuce and 1–2 pickle slices. Place the cheesy smashed patty on top, add a generous pinch of crispy fried onions, and top with additional pickles or a thin raw onion ring if desired. Finish with the top bun spread lightly with sauce or left plain. Serve immediately.

Classic Burger Sauce

In a small bowl, whisk together 1/2 cup mayonnaise, 2 tablespoons ketchup, 1 teaspoon yellow mustard, 1 tablespoon sweet pickle relish, 1/2 teaspoon Worcestershire sauce, 1/2 teaspoon apple cider vinegar, 1/4 teaspoon onion powder, 1/4 teaspoon smoked paprika and 1/4 teaspoon salt until smooth. Taste and adjust seasoning; refrigerate until ready to use. Makes slightly more than needed for 4 burgers; stores covered in refrigerator for up to 3 days.

Crispy Fried Onions

Prepare coating

Toss 1 cup thinly sliced onions with 1/2 cup all-purpose flour, 2 teaspoons cornstarch, 1/2 teaspoon salt and 1/4 teaspoon black pepper until evenly coated. Shake off excess flour into a bowl.

Fry onions

Heat about 1 cup vegetable oil in a small skillet over medium-high heat until it shimmers (about 350°F if using a thermometer). Fry the onion slices in batches, turning, for 1–2 minutes per batch until golden and crisp. Use a slotted spoon to transfer to a paper towel-lined plate and sprinkle immediately with a pinch of salt. Allow to cool; they will crisp further.