Crush the cornflakes: Pulse the cornflakes in a food processor, or crush them in a zip-top bag with a rolling pin, until they are coarse crumbs. Stir in the garlic powder and smoked paprika, if using, and pour into a shallow dish.
Make the batter: In a second shallow bowl, whisk the egg, milk, flour, salt, and pepper until smooth.
Preheat the air fryer: Preheat the air fryer to 350°F for 5 minutes. Lightly spray the basket with olive oil.
Bread the chicken: Pat the chicken dry. Dip each tender into the batter, let the excess drip off, then press it firmly into the cornflakes to coat all sides.
Air fry: Arrange the tenders in a single layer without touching and spray the tops with oil. Air fry for 5 minutes.
Flip and finish: Flip the tenders, spray again, and air fry for 3 to 5 minutes more, until the internal temperature reaches 165°F.
Rest and serve: Let the tenders rest for 2 minutes so the coating sets, then serve with your favorite dipping sauce.