Preheat oven to 350 degrees.  In a mixer, mix sugar, eggs, pumpkin, and oil until well combined.  Add in the flour, baking powder, baking soda, and cinnamon.  Pour mixture into a greased 9×13 pan.  Bake at 350 for 25-30 minutes, until a toothpick comes out clean.

While the pumpkin bars are baking, cream together the butter, cream cheese, and vanilla extract.  Add in the powdered sugar gradually until the icing reaches desired consistency.

When the pumpkin bars come out of the oven, cool completely before frosting.  For extra decoration, place a candy pumpkin on top of each bar.