Preheat oven to 350°F. Spray a 9x13 inch baking dish with nonstick cooking spray.
Place cream cheese in a microwave-safe bowl, cover with paper towel, and heat in 15-second intervals until very soft.
In a large bowl, mix softened cream cheese, sour cream, and salsa until smooth. Add shredded chicken and mix well to combine. Season with garlic powder, salt and pepper if desired.
Pour about half the enchilada sauce into the bottom of the prepared baking dish.
Warm tortillas according to package directions to make them pliable.
Place about 1/2 cup of chicken mixture down the center of each tortilla. Top with 1-2 tablespoons of cheese.
Roll tortillas tightly and place seam-side down in the prepared dish.
Pour remaining enchilada sauce over the top and sprinkle with remaining cheese.
Cover tightly with foil and bake for 25-30 minutes.
Remove foil and bake an additional 5 minutes or until cheese is melted and bubbly.
Let stand 5 minutes before serving. Top with desired garnishes.