Preheat oven to 350 degrees F. Slice pumpkin in half and remove stem. You can cut it in quarters if you want, or just leave it halved. Using a spoon, scrape out all of the stringy stuff and the seeds. (Save the seeds if you want to toast them). Spray a foil-lined baking sheet with non-stick spray. Place your pumpkin cut-side down on the sheet. Cook pumpkin in a 350 degree oven for about 45 minutes or until it's tender when pierced with a fork. When done, remove from oven and let cool on the baking sheet.
Using a spoon scrape out the flesh and discard the skin/rind. It should be easy to scoop right out. Place pumpkin pulp in a food processor and process until smooth. I used the blade attachment of my Cuisinart hand mixer. You can also just mash it with a fork or potato masher. If your pumpkin is on the dry side, you can add a little water to the pumpkin to get the consistency you want.
I drizzled in about 1/4 cup of water until it had the right feel. At this point you can use it in any recipe that calls for pumpkin puree or canned pumpkin. I froze mine in 2 cup measures in zip lock freezer bags. Most recipes I use call for a whole can which is 15 ounces. If the pumpkin puree has a little water in it just place the puree in a strainer and strain off the water before storing.
*Note: If the skin of you pumpkins is really hard you can bake the pumpkins whole for about 20 minutes first. Then remove from the oven let cool a bit and cut in half and proceed with the recipe as listed.
Recipe yields: about 4 cups pumpkin puree