Preheat oven to 375 degrees F, line 8 x 8 square baking dish with parchment paper and spray with cooking spray. Set aside.
In a medium mixing bowl, whisk together pumpkin puree, applesauce, egg whites, maple syrup, vanilla extract, pumpkin pie spice, baking powder, baking soda and protein powder. Add oats, walnuts and stir well.
Pour mixture in prepared baking dish, level with spatula and bake for 35 minutes or until a toothpick inserted in the center comes out clean.
Remove from the oven, let cool for 10 minutes and transfer to a cooling rack to cool for another 30 minutes. Cut with a serrated knife into 8 or 10 bars. Serve warm or cold.
Notes
Store: Refrigerate in an airtight container for up to 1 week
Freeze: Tightly wrapped for up to 3 months.
Eggs: Bars made with eggs will come out more moist and rich, but for a leaner version use egg whites. They still are super moist.
Portion size: For smaller portions cut into 10 bars.