1. Preheat oven to 350°. Place 8 paper liners in muffin tin; coat with cooking spray.
2. Combine applesauce and next 4 ingredients. In a separate bowl, whisk together the next 6 ingredients. Add oat mixture to applesauce mixture; stir until blended. Stir in chocolate chips.
3. Spoon batter into muffin cups. Bake for 20–22 minutes, rotating the pan a half-turn after 10 minutes. Muffins are done when tops are firm to the touch.
4. Cool slightly. Top with powdered sugar, if desired.