Step 1

For the pickles:

Step 2

Combine the water, vinegar, salt, sugar, pickling spice and pepper flakes in a small saucepan. Bring to a simmer over medium heat.

Step 3

Meanwhile, combine the cucumbers, dill and garlic in a heat-resistant quart-size jar and set aside.

Step 4

Once the vinegar mixture comes to a simmer, turn off the heat. Pour the mixture over the cucumbers and let cool to room temperature. Cover the jar and store in the refrigerator for at least 24 hours before enjoying.

Step 5

For the special sauce:

Step 6

Whisk together all the ingredients in a small bowl. Taste and adjust as desired.

Step 7

For the caramelized onions:

Step 8

Melt the butter in 1 tablespoon of the oil in a large saucepan over medium-high heat. Add the onions and season with salt and pepper.

Step 9

Cook, stirring occasionally, for 15 minutes.

Step 10

Reduce the heat to medium and cook, stirring frequently, for another 10 minutes.

Step 11

Reduce the heat to medium-low and continue to cook another 5 to 10 minutes, until the onions are deep golden brown. Stir in the thyme leaves and remove from the heat. Place in a bowl to cool. Store in an airtight container for up to 1 week in the fridge.

Step 12

For the burgers:

Step 13

Using a box grater, grate the frozen stick of butter on the smallest size holes. Combine the beef, grated butter, salt, pepper and garlic powder in a large bowl — don't overmix. Divide into 8 portions and loosely form into balls, about 4 ounces for each. Cover with plastic wrap and set aside.

Step 14

Preheat a gas or charcoal grill to high heat (450 F to 500 F) with a cast-iron griddle on it. You want it smoking hot.

Step 15

Split the buns and slather with mayonnaise on each cut side.

Step 16

Toast the burger buns on the hot griddle for 1 to 2 minutes, until golden, making sure not to burn them. Remove from the heat.

Step 17

Working quickly, place 4 of the burger balls on the griddle on the grill and, using a spatula and a piece of parchment paper just bigger than the final patty size, smash the ball into a thin burger. You want to really put some weight into it to make it as thin as possible. You can even use another metal spatula to assist in the smash. Slide the spatula off (don't pull it up). This will help the patty stay flat against the griddle.

Step 18

Cook for 3 to 4 minutes and, at the end, add a few slices of onion, then quickly flip the patties and give them another smash with the spatula. Top each patty with sliced cheese, close the lid on the grill, and cook another 3 to 4 minutes, until the cheese is melted.

Step 19

Stack 2 patties and place them on the bottom bun. Top with desired toppings and the top bun.