1Mix flour, baking soda, baking powder, salt and cinnamon and set aside.
2Beat sugar, pumpkin, oil, and eggs until well incorporated.
3Gradually add dry ingredients into pumpkin mixture until fully incorporated.
4Pour mixture into an ungreased 15x10x1 pan and bake at 350 degrees for 25-30 minutes. Let cool completely before frosting.
5For the cream cheese frosting:
Beat together butter, cream cheese, vanilla until incorporated. Gradually add powdered sugar, and taste as you go. I like my frosting a little less sweet so I end up using less than the full amount of powdered sugar. Once frosted, I garnish with cinnamon on top.
(I died the frosting orange in the picture for Halloween and topped with fresh ground cinnamon)