Preheat oven to 350 degrees F. Liberally grease a 15x10" jelly roll pan. Set aside.
In a bowl of a stand mixer, beat together the sugar, pumpkin, oil, vanilla and eggs until blended. Gradually add in the flour, baking powder and soda, and spices and beat to combine. Pour the mixture into the prepared baking pan.
Bake for approx. 20-25 minutes or until cake springs back lightly when touched and a toothpick inserted near the center comes out clean or with moist crumbs. Cool completely.
Once cake has cooled, prepare your icing. In a large bowl of a stand mixer, cream together the butter, cream cheese and vanilla until creamy and blended. Add in the powdered sugar, about a cup at a time, until frosting is light and fluffy. You may need to use the cream to thin out the frosting a little.
Spread the frosting onto the cooled cake, cut into slices and serve. Store leftovers covered in the fridge.