In a small bowl, combine the oats and milk. Cover, refrigerate, and let sit for 1 hour.
Preheat oven to 400 degrees. Line a muffin pan with cupcake liners or spray with nonfat cooking spray.
In a medium sized bowl, combine flour, baking powder, baking soda, salt and sugar.
Remove oats from refrigerator, and add in the egg, applesauce, and vanilla extract.
Add the wet mixture to the dry, and stir until just combined. Do not over mix.
Pour muffin mixture into muffin pan, and place in oven. Bake for about 15 minutes or until muffin is cooked through and a toothpick comes out dry when inserted. Remove from muffin pan and place on cooling rack.