01 - In a mixing bowl, combine the pickle juice, sugar, garlic powder, onion powder, smoked paprika, black pepper, and hot sauce. Add the chicken cutlets, ensuring they are fully submerged in the brine. Cover the bowl and refrigerate for a minimum of 2 hours, or up to 8 hours, to allow the flavors to penetrate.
02 - Remove the chicken cutlets from the brine and thoroughly pat them dry with paper towels. Set up three separate shallow bowls or plates. The first bowl should contain the all-purpose flour, salt, black pepper, and paprika. Whisk the eggs and milk together in the second bowl. The third bowl should be filled with the panko breadcrumbs.
03 - Working with one chicken cutlet at a time, first dredge it in the seasoned flour mixture, shaking off any excess. Next, dip the floured cutlet into the egg and milk mixture, allowing any excess to drip off. Finally, press the cutlet into the panko breadcrumbs, ensuring it is fully coated on all sides.
04 - Pour approximately 1/2 inch of vegetable oil into a large skillet or deep pan. Heat the oil over medium-high heat until it shimmers. Carefully place the breaded chicken cutlets into the hot oil, being careful not to overcrowd the pan. Fry for 3–4 minutes per side, until the chicken is golden brown and cooked through, reaching an internal temperature of 165°F (74°C). Remove the cooked chicken from the skillet and drain on paper towels.
05 - Lay out all 8 slices of bread on a clean work surface. On 4 of the bread slices, arrange 2 slices of sharp cheddar cheese. Place one fried chicken cutlet on top of the cheese on each of these 4 slices. Top each chicken cutlet with another slice of sharp cheddar cheese. Finally, place the remaining 4 slices of bread on top to complete the sandwiches.
06 - Heat a clean skillet or griddle over medium heat. Lightly spread softened unsalted butter on the outside of each slice of bread for the sandwiches. Place the assembled sandwiches onto the preheated skillet or griddle. Grill for 2–3 minutes per side, pressing down gently with a spatula, until the bread is golden brown and toasted, and the cheese is fully melted and gooey.
07 - Remove the grilled sandwiches from the skillet. Slice each sandwich in half diagonally and serve immediately while hot for the best texture and flavor.