Pumpkin Bars

I should really call these My Favorite Pumpkin Bars.  I've been making them for more years than I claim to be alive, and they come out perfectly every time.

They're moist and flavorful, deceptively easy to whip up, and this recipe makes 30 bars, perfect for a crowd.  You bake them in a rimmed cookie sheet, and they come out thick, like cake.  It's a shame we wait until fall to make pumpkin desserts-- these are good enough to enjoy all year!
Here's what you need:

4 eggs
1 & 2/3 Cup sugar
1 Cup cooking oil
1 (16 oz) can solid pack pumpkin
2 Cups flour
2 teaspoons cinnamon
2 teaspoons baking powder
1 teaspoon salt
1 teaspoon baking soda

Frosting:
1 (8 oz.) pkg. cream cheese, softened
1/2 Cup (1 stick) butter, softened
1 teaspoon vanilla
2 Cups powdered sugar, sifted

1. Preheat oven to 350 degrees.  In a large bowl, beat eggs, sugar, oil, and pumpkin until well mixed.  Sift flour and remaining dry ingredients into batter.  (It's worth it to sift, to prevent little white lumps in the batter.)  Mix thoroughly, then spread on an UNgreased (10x15-inch) baking sheet.  Bake 25 minutes, or until knife tests clean when inserted in center.  Cool, frost, then cut into bars.
To make frosting:
In a medium bowl, beat cream cheese, butter, and vanilla until smooth.  Add sifted powdered sugar a little at a time, beating until smooth.  (Again, worth it to sift the sugar so you don't get lumps.)