Preheat oven to 400 degrees F (200 degrees C). Spray 16 muffin cups with cooking spray.
Sift flour, baking powder, and cinnamon together in a bowl. Mix sugar, applesauce, milk, egg, and vanilla extract together in a separate bowl. Stir flour mixture into wet ingredients until just combined. Fold in blueberries. Fill muffin cups 2/3 full with batter.
Bake in the preheated oven until a toothpick inserted in the center of a muffin comes out clean, 20 minutes.
