In a medium bowl, combine the chicken thighs with the buttermilk, ensuring the chicken is completely submerged. Cover and refrigerate for at least 1 hour.
In a separate bowl, mix the all-purpose flour, paprika, garlic powder, onion powder, salt, black pepper, and cayenne pepper. Set aside.
In a deep skillet or Dutch oven, pour enough vegetable oil to create a depth of about 1-2 inches and heat over medium-high heat until it reaches 350°F (175°C).
Remove the marinated chicken from the buttermilk, allowing excess liquid to drip off. Dredge each piece in the seasoned flour mixture, pressing down firmly.
Carefully lower the coated chicken thighs into the hot oil. Fry for about 5-7 minutes on one side until golden brown, then flip and continue cooking until the internal temperature reaches 165°F (75°C). Transfer to a paper towel-lined plate.
In a small mixing bowl, combine the honey with the finely chopped jalapeños. Stir well and set aside.
Toast the brioche buns until golden brown. Spread jalapeño honey on the bottom half of each bun, add the fried chicken, leafy lettuce, tomato slices, and pickles. Drizzle extra jalapeño honey over the chicken before placing the top half of the bun on.
Serve the sandwiches immediately while hot, with additional jalapeño honey on the side.
Notes
Adjust the cayenne pepper according to your spice preference.