Begin by making your burger sauce. In a bowl, mix together mayo, ketchup, pickle juice, diced pickles, sugar, vinegar, paprika and salt and pepper. Set aside.
Divide your ground beef into 4 equal portions and shape them each in a ball and then a patty. Make a small dent with your thumb half way through the middle of the patty - this will help with even cooking and keeping your patties flat.
Tip: Season on both sides with salt and pepper. You can alternatively just season one side, then when you put them on the grill, put them on the grill seasoned side down, and season the other side on the pan itself.
In the meantime, slice, butter and toast your buns, set aside.
Heat a cast-iron griddle or skillet until very hot and then drizzle on a little bit of vegetable oil.
Working in batches, place your patties on the skillet. Place a spatula on top of the patty to push down a tad to get an even char and flatten it out a tad. If you want to make this a smash burger, don't form patties and place your sectioned ball on the skillet and smash it down as thin as you can with the spatula, 1-2 minutes until golden brown and then flip! When it’s crispy on the bottom (about 3-4 minutes), flip, and place a slice of cheese on the top of each patty. Cook until the cheese is melted, about 1-2 minutes.
Serve your patties on your buttered buns with your burger sauce, lettuce, tomato, and pickled red onions. Serve and enjoy!