Preheat oven to 350 degrees F. Grease a 10 by 15-inch jelly roll pan.
In a large bowl mix together the pumpkin, sugar, eggs, and salad oil with an electric mixer.
Sift together the flour, baking powder, baking soda, salt, cinnamon, ginger, nutmeg, and cloves.
Add the sifted dry ingredients to the pumpkin mixture and mix until well combined.
Spread the batter in the prepared jelly roll pan. Bake in the preheated oven for 25 to 30 minutes or until the center is set.
Remove from oven and cool completely
While bars are cooling make the frosting.
With an electric mix beat the cream cheese until fluffy. Add the butter and beat until well combined. Mix in the milk and the vanilla. Add the powdered sugar and beat until creamy.
Spread over cooled bars.