Choose your Pumpkin - You should seek out a pie pumpkin, or sugar pie pumpkin. These pumpkins are less grainy and stringy than jack-o-lantern pumpkins and make better pies and baked goods. Choose a pumpkin that is weighty. Your pumpkin should feel heavy. If it feels light, it is old and dry inside.
Halve the pumpkin - A cleaver or any large sharp knife will do – just be careful to not put your fingers underneath the knife either on the pumpkin or your work surface, and don’t wrap your hand around the knife for leverage.
Scoop out seeds, saving them to roast for later. Scoop out strings with a spoon. Cut each pumpkin half into quarters.Bake the Pumpkin - Place in 9x13 inch baking dish. Add only enough water to come up to the thick skin of the pumpkin – no more than that, or the pumpkin will get waterlogged and mushy. You want the pumpkin to steam, not to soak up water. Cover the baking dish with tin foil. Bake at 350 for 45 minutes to 1 hour, until a toothpick easily pierces the skin and goes through the flesh of the pumpkin.
Let cool. Take the skin off the pumpkin – you can peel it with a butter knife. If properly baked, the pumpkin in your hand should feel like soft cream cheese. It should not be watery or fall apart into pieces. If the pumpkin feels waterlogged, put the skinned pieces in a sieve over a bowl. Refrigerate overnight –the water should drain out of the pumpkin and into the bowl. (I follow this step regardless, just to make sure as much water comes out of the cooked pumpkin as possible.) Discard the water.
Make the Pumpkin Puree - Puree the pumpkin in a food processor. You will need to stop the machine a couple of times to push the pumpkin down with a spatula, so it all gets processed smoothly. Be patient, this will take several minutes.
The pumpkin puree should be nice and thick when done – it should be able to stick to a spoon turned upside down and it should hold its shape when swirled. Store in the refrigerator until ready to use.
Roasting the Pumpkin Seeds - Clean the seeds in a colander over running water, fishing out any pumpkin pulp or strings. Spread on paper towels and blot dry. Remove seeds to a baking sheet. Drizzle with oil (canola, olive or grapeseed) and toss to coat. Sprinkle seeds liberally with salt. Bake at 250 degrees for 40 minutes. Increase the oven temperature to 350 degrees and bake another 5 minutes, or until seeds are golden brown (if they start popping like popcorn in the oven, take them out – they are done!).