Preheat oven to 425°F and spray a large baking sheet with cooking spray.
In a large bowl, combine chicken, cheese, salsa, and sour cream. Season with salt and pepper.
Spoon about 3 tablespoons of chicken mixture in a line down the center of each tortilla. Tightly roll tortilla around mixture. Place taquitos seam-side down onto prepared baking sheet, making sure they aren’t touching so that they can get crispy all over. Spray generously with cooking spray and season with salt and pepper. I also sprinkled some chili powder and cayenne on top, but not necessary!
Bake for 12 to 15 minutes, until golden brown and crispy. While the taquitos are cooking, chop up your lettuce and prepare any other toppings you’re going to serve with your taquitos. Serve immediately with desired toppings.