I brew more pumpkin beers than just about anything else as most everyone I know goes nanners over it around this time of year.
I get whats called sugar baking pumpkins(they are not orange like traditional ones, but not white..kind of a pale orange but they are AWESOMELY sweet!).
The only place I have found these is up in the mountains of NC on the side of the road stands.
I cut open, gut it and cut it into quarters. Tin foil on a deep baking dish and into the over at 350 for an hour and a half. The pumpkin will literally start to look like its deflating and the skin will start bubbling.
Take it out, let it cool and the pumpkin meat should just be very soft. Seperate it from the skin, mash it up. Pour any of the clear pumpkin juice from the baking sheet right into the mashed up pumpkin. That pumpkin juice is liquid gold man.:rockin:
For the mash in, I usually mash in a little higher temp-wise if the pumpkin is 100% cooled..Mash in my grains(no doughballs) and then just plop the pumpkin on top of the grains so the strike water is just over the top of the pumpkin. Let it sit for 45mins, stir gently and 15 mins later, collect my first wort runnings.
I batch sparge and stir more on the sparge than on the strike in with the pumpkin involved, but still dont get many stuck sparges using whole pumpkin. Canned pumpkin is another story. That stuff disintegrates into the mash and sticks my sparge 75% of the time.
I always hit my SG with this method and never had an issue. Finding GOOD whole pumpkins are a pain off season.