In a medium-sized mixing bowl, combine the buttermilk and hot sauce, whisking gently to blend. Add the chicken tenderloins into the mixture, ensuring they are fully submerged. Cover the bowl with plastic wrap and refrigerate for a minimum of 1 hour—overnight is best for maximum flavor infusion.
In a large shallow dish or pie plate, sift together the all-purpose flour, Cajun seasoning, paprika, garlic powder, onion powder, black pepper, and salt until evenly mixed.
In a deep skillet or frying pan, pour enough vegetable oil to reach a depth of about 1 inch. Heat the oil over medium-high heat until it registers 350°F (175°C) on a cooking thermometer.
Once marinated, take each chicken tender out of the buttermilk, allowing any excess liquid to drip off. Dredge each piece in the seasoned flour mixture, pressing lightly to ensure an even coating.
Carefully place the coated chicken tenders into the hot oil in batches, making sure not to overcrowd the pan. Fry for about 4-5 minutes on each side, or until they turn a rich golden brown and are cooked through.
Once fully cooked, use a slotted spoon or tongs to transfer the chicken tenders onto a plate lined with paper towels.