Prep: Preheat oven to 350°F (175°C) and grease a jelly roll pan or 10x15 inch baking pan.
Mix Wet: In a large bowl, beat eggs, sugar, oil (or applesauce mix), and pumpkin until smooth and glossy.
Mix Dry: In a separate bowl, whisk together flour, baking powder, baking soda, cinnamon, pumpkin pie spice, and salt.
Combine: Slowly add the dry ingredients to the wet mixture, stirring just until the flour disappears. Do not overmix.
Bake: Pour batter into the pan and spread to the corners. Bake for 25–30 minutes until a toothpick comes out clean.
Cool: Let bars cool completely to the touch before frosting to prevent melting.
Frost: Beat together cream cheese, butter, powdered sugar, vanilla, and maple syrup until smooth. Spread over cooled bars and slice.