Preheat oven to 350 degrees. Line a 15x10 inch jelly roll pan with parchment paper or grease the pan with butter.

Add the pumpkin, eggs, oil, brown sugar, granulated sugar, and vanilla to a large bowl and use a hand mixer or whisk to mix together until well combined.

Add the flour, pumpkin pie spice, cinnamon, baking powder, baking soda, and salt to the bowl and mix until well combined.

Spread the mixture into the prepared pan and bake for 30-35 minutes or until a toothpick inserted near the center of the pan comes out clean. Tent with foil halfway through baking if the edges are getting too browned.

Cool bars completely on the counter before frosting.

Beat together the cream cheese and butter in a large bowl with an electric mixer until smooth and creamy.

Add the powdered sugar, vanilla, and salt and continue mixing for 2-3 minutes or until frosting is thick and creamy.

Spread the frosting on the cooled bars.

Place in the refrigerator for at least 30 minutes before slicing and serving.