Prep

• In a large bowl, gently combine the ground beef, kosher salt, black pepper, garlic powder, onion powder, and Worcestershire sauce. Mix just until the seasonings are evenly distributed.
• Divide the beef into eight equal portions, about 3 ounces each, and loosely shape each into a ball without compressing the meat. Refrigerate until ready to cook.
• In a small bowl, whisk together the mayonnaise and mustard until smooth. Cover and refrigerate.
• Prepare the toppings by shredding the lettuce and slicing the tomato, onion, and pickles.
• Butter the cut sides of the hamburger buns.

Cook

• Heat a flat-top griddle or large cast-iron skillet over medium-high heat until very hot.
• Add the vegetable oil and spread it over the cooking surface.
• Toast the buns, cut-side down, until lightly golden. Remove and set aside.
• Arrange several beef balls on the hot griddle, leaving enough space between each for smashing.
• Place a square of parchment paper over each portion and press firmly with a burger press or heavy spatula until the patties are very thin.
• Remove the parchment and cook the patties undisturbed for about 2 minutes, or until the edges are deeply browned and crisp.
• Use a sturdy metal spatula to scrape completely underneath each patty and flip.
• Top four patties with a slice of cheddar cheese and cook for about 1 minute, until the cheese begins to melt.
• Place one plain patty on top of each cheeseburger patty to create four double burgers.
• Transfer the burgers to a plate and repeat with the remaining beef if necessary.

Assemble

• Spread the burger sauce over the bottom half of each toasted bun.
• Add shredded lettuce, pickle slices, tomato, and red onion.
• Place a double cheeseburger on top.

••Finish with the top bun and serve immediately.