Preheat the oven to 375 degrees F (190 degrees C).
Spray both sides of the tortillas with butter-flavored cooking spray. Cut small circles into the tortillas using a 2 3/4-inch round cookie or biscuit cutter. You should be able to get about 3 to 4 circles from each tortilla.
Flip two 12-cup muffin tins upside down. Fold tortilla circles into a taco shape and arrange each into the space between 2 cups so they hold their shape. Each muffin tin will hold 17 mini tacos.
Bake in the preheated oven until tacos are just starting to turn golden brown and crispy, checking every few minutes to make sure they don't burn, 5 to 8 minutes.
Mix together chicken, corn, and salsa in a skillet and set over medium-high heat. Cook, stirring occasionally, until heated through, about 10 minutes.
Sprinkle cheese blend into the bottom of each taco shell, and fill with the chicken and corn mixture. Top with a dollop of sour cream.