First, much of the flavor of pumpkin pie is actually in the spices. So I would plan on a spiced pumpkin ale if you want a "pumpkin pie" taste.
Secondly, I recommend a high mash temp, if you are doing AG. That will give you more mouthfeel. If you are doing Extract batches, then try steeping a pound of carapils for some mouthfeel.
In Process: Mango Beer, Homebrewers Pale Ale
Bottled/Kegged:Spicy Light Rye, Rice-adjunct Pale Ale, Mild Bourbon Porter, Roasty Stout, Basic Light Mead, Bourbon County Stout Clone
Up Next: Berlinerweiss, Chocolate Raspberry Ale, and American IPA