In a mixing bowl, beat eggs, sugar, oil and pumpkin. Combine flour, cinnamon, baking powder, baking soda and salt; gradually add to pumpkin mixture and mix well. Pour into an ungreased 15-in. x 10-in. x 1-in. baking pan. Bake at 350 degrees F for 25-30 minutes. Cool completely.
For icing, beat cream cheese, sugar, butter and vanilla in a small mixing bowl. Add enough of the milk to achieve desired spreading consistency. Spread over bars.