Preheat oven to 350 degrees and spray a 8x8 baking pan with cooking spray.
Sift together all the dry ingredients (flour, pumpkin pie spice, baking soda, and salt) listed above into a large mixing bowl. Set aside.
In the bowl of a stand mixer, cream together butter, sugar, egg, and applesauce.
Add the dry ingredients into the mixture and combine well.
Pour mixture into prepared baking dish.
Make the cinnamon spice mixture by combining all the ingredients listed above (brown sugar, flour, cinnamon, and butter).
Sprinkle mixture on top of batter and place into preheated oven.
Bake for 30-35 minutes until center of bars are completely baked and golden brown in color.
Let bars cool for 15 minutes before enjoying.
Store in an airtight container for up to 3 days after baking!
