Start by slicing the jalapenos half lengthways and removing the seeds and membranes. If you would like more heat in your jalapeno poppers, you can leave some of the seeds or add them to the filling.
Add the cream cheese, shredded cheddar cheese, garlic powder, and red pepper flakes in a large mixing bowl, and mix well until the filling has formed.
Use a teaspoon to fill the jalapeno halves; depending on the size of the jalapeno peppers, they will need about two teaspoons of filling.
Preheat the air fryer to 360 degrees F. Using the air fryer setting, preheat for 3-5 minutes. Spray the cooking spray over the tray at the bottom of the air fryer. Dip each jalapeno pepper into the egg whites and then into the cornflake crumbs.
Place the coated jalapeno peppers into the air fryer basket, and spray lightly with cooking spray; set the cooking time for 7-10 minutes.
Remove from the air fryer, and serve with your favorite dipping sauce or garnish with fresh herbs.