01 - In a bowl, combine chicken pieces, pickle brine, and hot sauce if using. Cover and refrigerate for at least 2 hours, or up to 8 hours for deeper flavor penetration.
02 - Remove chicken from the brine and pat thoroughly dry with paper towels to ensure proper breading adhesion.
03 - In one shallow bowl, whisk together flour, cornstarch, garlic powder, onion powder, smoked paprika, salt, and pepper. Pour buttermilk into a separate shallow bowl.
04 - Dip each chicken piece into the flour mixture, then into the buttermilk, then back into the flour mixture, pressing 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 maintain consistent temperature.
06 - Fry chicken pieces in batches, being careful not to overcrowd the pan, until golden brown and cooked through to an internal temperature of 165°F, approximately 3 to 4 minutes per side. Drain on a wire rack set over a sheet pan.
07 - Lightly toast slider buns cut-side down in a dry skillet or under a broiler until golden.
08 - Spread mayonnaise on each bun bottom, layer with a lettuce leaf, a piece of fried chicken, and a dill pickle slice. Cap with the top bun half and serve immediately while warm.