Coat a 9-inch glass baking dish with cooking spray.
In a microwave-safe bowl, combine cheese product and sour cream; cover and microwave on high power until cheese melts, about 1 1/2 to 2 minutes. Remove half of melted cheese to a small bowl and stir in evaporated milk; set aside.
Add scallions, red pepper flakes and chicken to remaining cheese mixture; stir to coat.
Spoon about 2/3 cup of chicken mixture down center of each tortilla; fold in sides of tortilla to cover filling and place tortillas in a single layer in prepared dish; spoon remaining cheese sauce over top and then sprinkle with shredded cheddar cheese and olives.
Bake until cheese topping is bubbly, about 20 to 25 minutes.