In a large bowl, combine the buttermilk and hot sauce. Add the chicken thighs, ensuring they are fully submerged. Cover and refrigerate for at least 2 hours, or overnight for best results.
In another bowl, mix together the flour, paprika, cayenne pepper, garlic powder, onion powder, salt, and black pepper.
Heat about 1 inch of vegetable oil in a large skillet over medium-high heat until it reaches 350°F.
Remove the chicken from the buttermilk, allowing excess to drip off. Dredge each piece in the flour mixture, pressing gently to ensure an even coating.
Carefully place the coated chicken in the hot oil, frying in batches if necessary to avoid overcrowding. Cook for about 5-7 minutes per side, or until golden brown and cooked through (internal temperature should reach 165°F).
Once cooked, transfer the chicken to a paper towel-lined plate to drain excess oil.
To assemble the sandwiches, place a piece of fried chicken on the bottom half of each bun. Top with pickles and coleslaw, then add the top half of the bun. Serve immediately.