In a bowl, combine chicken, egg, mayonnaise, sweet chili sauce, and soy sauce. Marinate for at least 20 minutes or up to overnight in the refrigerator.
Preheat oven to 425°F. Line a baking sheet with parchment paper; brush with oil.
Crush corn flakes very well with your hands until they reduce from 4 cups to 1½ cups. Add crushed corn flakes to a shallow dish.
Remove chicken from marinade; coat in crumbs. Place on prepared baking sheet.
Spray tops of schnitzel very well with nonstick cooking spray or brush with additional oil. Bake for 15-20 minutes, until crispy (time will depend on the thickness of the chicken).