In a large bowl, whisk together buttermilk, hot sauce, salt, and black pepper. Add chicken thighs, ensuring they are fully submerged. Cover and refrigerate for at least 2 hours, preferably overnight.

In a separate bowl, mix together flour, paprika, cayenne pepper, garlic powder, onion powder, salt, and black pepper.

Remove chicken from the marinade, allowing excess to drip off. Dredge each piece in the flour mixture, pressing gently to adhere. Shake off excess flour.

In a large frying pan, heat vegetable oil over medium-high heat until it reaches 350°F (175°C). Fry chicken in batches, cooking for about 8-10 minutes per side, or until golden brown and cooked through. Use a thermometer to check that the internal temperature reaches 165°F (74°C).

Remove chicken from the oil and place on paper towels to drain excess oil. Serve hot.