Now we're going to start cooking with the pumpkin, and first we have to make the pumpkin mush. With all of the seeds and stringy insides scooped out, slice the pumpkin into small (6 to 8 inch) sections. Rub the insides with melted butter and place the pumpkin pieces face down (skin side up) on baking sheets. Bake at 350 degrees F for about an hour. Lots of juices will run out - and since I didn't put anything under my baking sheet, I got to clean out my oven the next day.
When the pumpkin is cool enough to handle, peel off the skin and place the pieces in a food processor. A few pulses will turn it to mush. Depending on how liquidy the mush is, you may want to cook some of the water out of it until it has a thicker consistency. Store your pumpkin mush in an airtight container in the refrigerator and freeze any that you don't use within a week.
The mess factor is pretty high here, so I didn't take many pictures during the process. I found a great blog though that has awesome pictures and detailed instructions on cleaning and prepping your pumpkin. I didn't use water and they didn't use butter. If you're gonna skip one, it's gotta be the water.