Sift together the flour, baking soda, baking powder, salt and spices, and set aside.
In a separate bowl, beat together the eggs, oil, sugar and pumpkin. Gradually add the dry ingredients and mix well.
Pour the batter into an ungreased jelly roll pan (17 x 12 inches) and bake for 15-20 minutes or until a toothpick inserted in the middle comes out clean. You can also used a 9 x 13 inch pan and bake for 25-30 minutes. Let cool on a wire rack and frost.
To make the frosting, beat together the cream cheese, butter, vanilla and milk. Add the powdered sugar one cap at a time, blending well after each addition. Add more milk if necessary.