Spray 14 muffin cups with cooking spray or line with paper liners; set aside.
In a large mixing bowl, add the flour, baking powder, baking soda, salt, and cinnamon. Stir to thoroughly combine and set aside.
In a separate bowl, whisk the egg and stir in brown sugar. Add canola oil, peanut butter banana, and vanilla until well combined. Fold in the shredded apple. Next fold in the dry ingredients until just combined. Avoid over-mixing.
Spoon the batter into the prepared muffin pan or cups until nearly full. Bake for 5 minutes. Reduce the oven temperature to 350℉ and bake for an additional 15 minutes or until a toothpick inserted into the center comes out clean. Remove the muffins from the pan immediately and cool for 10 minutes before serving.