On low speed, beat eggs with an electric mixer until fluffy. Add sugar, maple syrup, applesauce and pumpkin.Continue to beat for 3-4 minutes until thoroughly mixed.
In a small bowl, mix together flour, cinnamon, pumpkin seasoning, baking powder and baking soda.
Add flour mixture to pumpkin mixture and beat for a minute until combined. Be careful not to over mix.
Bake in preheated oven for 30-35 minutes until toothpick placed in the center comes out clean.
While bars are cooking, cook butter in large saucepan over medium heat until browned, about 15-20 minutes, making sure to stir occasionally.
Remove from heat and add the remaining ingredients while continuing to stir to avoid clumps.
Allow bars to cool completely before icing. Store in an airtight container for 3-4 days.