In a small bowl, whisk together mayonnaise, ketchup, yellow mustard, sweet pickle relish, Worcestershire sauce, smoked paprika, and garlic powder until well combined. Set aside.

In a large mixing bowl, gently combine the ground beef with salt and black pepper. Do not overmix. Divide the beef into 12 equal portions (about 2 ounces each) and gently form into small, flat patties slightly larger than your slider buns, as they will shrink when cooked.

Preheat a large skillet or griddle over medium-high heat. Place the beef patties in the hot skillet, working in batches if necessary, and cook for 2-3 minutes per side, or until desired doneness. During the last minute of cooking, place a quartered slice of cheese on top of each patty, covering it with a lid for 30 seconds to help the cheese melt. Remove patties from the skillet and set aside.

Preheat your oven to 350°F (175°C). Separate the tops and bottoms of the slider buns. Arrange the bottom halves of the buns in a single layer on a baking sheet.

Brush the inside of both the top and bottom bun halves lightly with melted butter.

Place a cooked cheeseburger patty on each bottom bun. Top with a few thin slices of red onion and a couple of dill pickle chips.

Spread a generous spoonful of the special sauce on the inside of each top bun, then place the top buns onto the assembled sliders.

Bake for 5-7 minutes, or until the buns are lightly toasted and the cheese is fully melted and bubbly.

Carefully remove the sliders from the oven. Serve immediately with any remaining special sauce on the side.