Marinate the chicken: In a bowl, whisk buttermilk, egg, hot sauce, and 1 teaspoon salt.
Add chicken tenders, toss to coat, and chill for at least 30 minutes. For extra tender meat, marinate up to 4 hours.
Mix the dredge: In a shallow dish, combine flour, cornstarch, black pepper, garlic powder, onion powder, smoked paprika, and 1 teaspoon salt. Stir well so the spices are evenly distributed.
Heat the oil: Fill a heavy pot with 2 inches of oil.
Heat to 350°F (175°C). Use a thermometer for accuracy. Keep the heat steady to avoid greasy or soggy results.
Dredge the tenders: Lift chicken from the buttermilk, letting excess drip off.
Press each piece into the flour mixture, coat fully, then dip back into the buttermilk, and dredge in flour again for a double coat. Place on a rack to rest 5–10 minutes. This helps the crust set.
Fry in batches: Fry 3–5 tenders at a time for 4–6 minutes, turning once, until golden and crisp.
Internal temperature should reach 165°F (74°C). Move cooked tenders to a rack set over a sheet pan. Let the oil return to 350°F between batches.
Make the hot oil: Carefully ladle 1/2 cup of the hot frying oil into a heatproof bowl.
Stir in cayenne, brown sugar, smoked paprika, garlic powder, salt, and cumin. The spices will bloom in the hot oil, turning deep red and aromatic.
Coat the tenders: Brush or spoon the hot oil over the fried tenders while they’re still warm. For extra punch, coat both sides.
Adjust heat by adding more or less cayenne to the oil.
Serve: Lay slices of white bread on a plate, top with tenders, and finish with crisp dill pickles. A squeeze of lemon brightens the heat if you like.