In a medium bowl, whisk together the buttermilk, egg, and ¼ teaspoon of the kosher salt.
Add the chicken tenders to the mixture and marinate for 15 minutes.
In a shallow bowl, combine the flour, cornstarch, garlic powder, onion powder, smoked paprika, remaining salt, black pepper, cayenne pepper, and dried oregano.
Pour the oil into a deep skillet or heavy-bottomed pan and heat to 350°F (175°C).
Remove each chicken tender from the marinade and dredge it in the flour mixture.
Dip the coated tender back into the buttermilk mixture, then coat it again in the flour mixture for an extra crispy crust.
Place the coated tenders on a wire rack while preparing the remaining pieces.
Fry the chicken in batches, avoiding overcrowding the pan.
Cook for 3–4 minutes per side, or until golden brown and the internal temperature reaches 165°F (74°C).
Transfer the cooked tenders to a clean wire rack to drain and maintain crispiness.
Serve immediately with your favorite dipping sauces and side dishes.