In a small Mixing Bowl, mix together the 3 tbsp mayonnaise, 2 tbsp ketchup, 1 tbsp yellow mustard, 8 dill pickles, and ½ tsp white vinegar until smooth. Cover and refrigerate until ready to serve.

In a large Mixing Bowl, gently combine the 1 ½ lb beef, 绞碎 (80/20混合优选), 1 tsp salt, 1 tsp salt, ½ tsp garlic powder, and 1 tbsp worcestershire sauce. Mix just until the seasoning is evenly distributed — do not overwork the meat or the patties will be tough.

Divide the mixture into 4 equal portions (about 6 oz each). Shape each into a round patty about 3/4-inch thick. Use your thumb to press a shallow indent into the center of each patty — this prevents them from puffing up during cooking.

Heat a Cast Iron Skillet over medium-high heat until very hot, about 2 minutes. Add the 1 tbsp butter and let it melt and begin to foam.

Add the patties to the Cast Iron Skillet without crowding. Cook undisturbed for 3–4 minutes until a deep brown crust forms on the bottom. Flip once and cook for another 2–3 minutes for medium doneness.

In the last 1 minute of cooking, place a slice of 4 slices of american cheese, 切片 on each patty. Cover the Cast Iron Skillet with a lid or large plate and let the cheese melt fully, about 1 minute.

While the cheese melts, toast the 4 brioche burger buns cut-side down in the same Cast Iron Skillet for 30–60 seconds until golden. Watch closely so they don't burn.

Spread the burger sauce on both halves of each toasted 4 brioche burger buns. Place a Lettuce Leaves on the bottom bun, then top with the cheeseburger patty, 1 tomato, 切片 (切成4片) slice, ½ red onion, 切片 (切成细圈) rings, and 8 dill pickles. Cap with the top bun and serve immediately.