In a large mixing bowl, combine the buttermilk, garlic powder, onion powder, smoked paprika, black pepper, and kosher salt. Whisk the ingredients together until the mixture is smooth and well blended.
Carefully place the chicken tenderloins into the buttermilk marinade, ensuring that each piece is fully submerged. Cover the bowl with plastic wrap or a lid, and refrigerate for at least 1 hour, or preferably overnight to enhance the flavor and tenderness of the chicken.
While the chicken is marinating, prepare the coating. In a separate large bowl, mix together the all-purpose flour, cornstarch, and baking powder. Stir well until fully combined and there are no lumps.
Once marination is complete, remove the chicken tenderloins from the refrigerator. Let the excess buttermilk drip off each piece before dredging it in the flour mixture. Ensure each tender is evenly coated, then shake off any extra flour mixture.
Heat about 1 inch of vegetable oil in a large, deep skillet over medium-high heat. Use a cooking thermometer to monitor the temperature, aiming for approximately 350°F (175°C).
Carefully add the coated chicken tenders to the hot oil in batches, ensuring not to overcrowd the pan, which could cause the oil temperature to drop. Fry each piece for about 4-6 minutes on each side, or until they are golden brown and have reached an internal temperature of 165°F (75°C).
Once cooked, use a slotted spoon to transfer the fried tenders to a paper towel-lined plate to absorb any excess oil.
Repeat the frying process with the remaining chicken tenders until all are cooked to crispy perfection.
Notes
Serve with your favorite dipping sauces and garnish with fresh herbs.