Pumpkin porter recipe... need some help

Hey all, August is drawing to a close which means fall will be coming shortly and I'm looking to start doing some brews for the coming cool weather. The big one I'm looking at doing is a pumpkin porter similar to the recipe in Extreme Brewing but I'd like to do it with canned pumpkin only. I've searched the forum over but can't find a good explanation on when to add the pumpkin either at the end of the boil or mash it? I'd like to do a really straight-forward recipe with extract, canned pumpkin and spices. Any recipes or insights?

This article may help you. Folks have been successful using both approaches. Just remember that most of the flavors associated with commercial pumpkin ales comes from the spices:

http://byo.com/stories/article/indices/38-ingredients/327-brewing-with-pumpkin-tips-from-the-pros

Cool, that link is awesome thanks for sharing! I think I will stick with the extreme brewing recipe and see how it turns out. I'm just always so damn antsy to add something to a recipe or try something new that I never can leave the original recipe well enough alone!