Best served cold.
Preheat oven to 350*F. Mix together pumpkin, sugar and oil. Add eggs, and mix well. In a separate bowl, combine flour, baking soda, cinnamon, and salt. Slowly add flour mixture into pumpkin mixture until well blended. Pour into greased 9 X 13 pan. Bake for 25-30 minutes, or until cake tests done (stick it with a toothpick). For frosting beat cream cheese, butter, and vanilla until smooth. Gradually add in the sugar, mixing well. Add one teaspoon of milk at a time until the frosting reached spreading consistency. Once cake is cool, spread with icing. Refrigerate (tastes best cold). Enjoy!