Preheat your oven to 350°.
In a large bowl, mix the eggs, oil, sugar, and pumpkin. Sift = the dry ingredients together in a separate bowl and mix into to pumpkin mixture. Mix well and pour into greased and floured 12x18 pan.
Bake at 350° for 25 to 30 minutes. Cool,
Meanwhile, in a large bowl, beat the cream cheese and butter until smooth. Add the remaining ingredients and continue beating until smooth. Spread evenly over the cooled bars.
OPTIONAL: Dust the top of the bars with a bit of freshly ground nutmeg for a finishing touch.
*You can substitute canned cream cheese frosting in a pinch.