Preheat oven to 180 degrees C. Grease and flour one 20x30cm tin and set aside.
In a mixing bowl, beat together the eggs, sugar, oil and pumpkin. Sift together the flour, baking powder, salt, bicarb soda and cinnamon; add to wet ingredients and mix thoroughly. Spread into prepared pan.
Bake for 25 to 30 minutes. Remove from oven and allow to cool.
Prepare the icing by beating together the cream cheese, butter and icing sugar. Evenly spread over cooled bars.