01 - In a bowl, combine the chicken pieces, pickle brine, and hot sauce if using. Cover tightly and refrigerate for at least 2 hours, or up to 8 hours for deeper flavor penetration.
02 - Take the chicken out of the brine and pat each piece thoroughly dry with paper towels to ensure the breading adheres properly.
03 - In a shallow dish, whisk together the flour, cornstarch, garlic powder, onion powder, smoked paprika, salt, and pepper. Pour the buttermilk into a separate shallow bowl.
04 - Dredge each chicken piece in the flour mixture, then dip into the buttermilk, and return to the flour mixture for a second coating. Press firmly to ensure full, even coverage on all sides.
05 - Pour about 2 inches of vegetable oil into a deep skillet or Dutch oven and heat to 350°F. Use a thermometer to monitor the temperature for consistent results.
06 - Carefully lower the breaded chicken pieces into the hot oil in small batches. Fry for 3 to 4 minutes per side until deep golden brown and cooked through to an internal temperature of 165°F. Transfer to a wire rack set over a sheet pan to drain.
07 - Lightly toast the slider buns cut-side down in a dry skillet or under a broiler until just golden.
08 - Spread a thin layer of mayonnaise on the bottom half of each toasted bun. Layer on a lettuce leaf, a piece of fried chicken, and a dill pickle slice. Cap with the top bun half and serve immediately while warm and crispy.