Using a stand mixer, or hand held, beat eggs and sugar together. Slowly add the oil.
Add pumpkin and beat until light and fluffy
In a bowl mix together dry ingredients and slowly incorporate until batter is smooth.
Pour batter into a non stick 12x18" or 13x18" sheet pan (with large lip on sides).
Put into a preheated oven at 350 degrees for 16-20 minutes or until middle springs back when touched lightly with your fingertip. ** If using 1 boxed cake mix prepared as directed on box, bake time is the same.
Allow to cool in pan completely before frosting.
In a bowl beat cream cheese and butter together, then add vanilla. Add powdered sugar gradually until it is as thick as you want it to be. Frost cake. Slice and serve.