In a large bowl, combine the buttermilk, hot sauce, salt, and black pepper. Whisk until well combined.

Add the chicken thighs to the buttermilk mixture, ensuring they are fully submerged. Cover and refrigerate for at least 2 hours, or overnight for best results. This tenderizes the chicken and infuses it with flavor.

In a separate bowl, combine the flour, paprika, garlic powder, onion powder, cayenne pepper, salt, and black pepper. Mix well to ensure even distribution of spices.

Remove the chicken from the marinade, allowing excess buttermilk to drip off. Dredge each piece in the flour mixture, pressing lightly to ensure an even coating. Shake off any excess flour.

In a large frying pan or deep fryer, heat the vegetable oil over medium-high heat until it reaches 350°F (175°C). Use a cooking thermometer to check the temperature, as this is crucial for achieving crispy chicken.

Carefully add the chicken pieces to the hot oil, being cautious not to overcrowd the pan. Fry in batches if necessary. Cook for about 12-15 minutes on each side, or until the internal temperature reaches 165°F (75°C) and the coating is golden brown.

Use tongs to turn the chicken halfway through cooking for even browning. Adjust the heat as needed to maintain the oil temperature.

Once cooked, remove the chicken from the oil and place it on a wire rack set over a baking sheet to drain excess oil. Let it rest for 5 minutes before serving. This helps the juices redistribute and keeps the chicken moist.

Serve hot with your favorite sides, such as coleslaw or mashed potatoes.