• Melt butter. Do not boil. Melt at low heat till just melted, not hot
• Mix butter, brown sugar, and granulated sugar together until well combined
• Stir in egg, egg yolk, and vanilla until well combined
• Add flour, salt, and baking soda. Stir until just combined
• Stir in chocolate chips until just incorporated
• Cover and chill dough at least 15-30 minutes
• Preheat oven to 325 F
• Line baking sheets with parchment or silicone baking mats
• Drop cookies by 1/4 cup scoop, spacing dough 3 inches apart
• Bake 15-20 minutes, or until edges are light brown and middles are set
• Let cookies cool before removing from trays

Portion Beef Patties:

• Divide beef into even portions, about 3 oz each (2 patties per serving). Loosely roll them into balls then cover and refrigerate while preparing remaining ingredients. The meat must be cold when it hits the grill.

Prep Toppings and Buns:

• Remove wilted leaves from lettuce to keep it crunchy then finely shred lettuce. Slice tomatoes, onions, and pickles.
• Butter and toast buns over medium heat until golden on the buttered side.

Cook the Patties:

• Increase griddle to medium/high heat. Place 2-4 burger balls onto hot griddle. Working quickly, place parchment paper over the meat and firmly smash straight down into a thin patty.
• Once patties are smashed, peel back and discard parchment papers and season patties with salt and pepper. Cook 2 minutes on the first side or until seared and juices start to come to the surface.
• Scrape under the burger with spatula facing down at a 45˚ angle to get under the caramelized part and flip. Cook another 1 minute. Top half of the patties with sliced cheese and cover cheese with the second patty. Repeat with remaining burgers and transfer them to a platter as they finish cooking.

Assemble Burgers:

• Place sauce on bottom of bun. Top with 3 pickle slices, shredded lettuce, 2 tomato slices and thin sliced onion. Add double patty and top with bun.