Preheat oven to 350F degrees. Spray a 10"x15" jelly roll pan with non-stick cooking spray and set aside. I like the nonstick spray that has flour in it.
In a large bowl or the bowl of a stand mixer, add the butter and sugars. Beat together until light and fluffy.
Add in the eggs, pumpkin and vanilla extract. Beat again until everything is combined and smooth.
In another bowl add the flour, baking soda and pumpkin pie spice. Whisk together until everything is combined.
Add in flour mixture to the wet mixture.
Fold in gently just until everything is combined and no flour streaks are left.
Spread batter into prepared baking pan and bake for about 22-25 minutes, remove from oven and let cool for at least an hour.
To make the frosting:
in a medium bowl, beat cream cheese and butter until fluffy.
Add powdered sugar, one cup at a time, until combined.
Then add vanilla and cinnamon and beat until smooth, spread over cooled bars.