Prepare pudding according to package directions. If using vanilla pudding, add a few spoonfuls of pumpkin puree. Gently fold entire container of frozen whipped topping into pudding. Spread a small amount(approx. 1/2 cup) of pudding mixture in the bottom of 9 x 13 pan.
Cover the pudding with a layer of graham crackers. Spread half of the remaining pudding mixture over the graham crackers.
Repeat with another layer of graham crackers and remaining pudding mixture. Cover with one final layer of graham crackers.
Microwave cream cheese icing for 10 - 15 seconds, until the icing is the texture of lightly whipped cream. Pour over top layer of graham crackers and smooth with spatula.
Cover and chill for at least 4 - 6 hours before serving.