Heat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
Rinse and scrub your pumpkin, then pat it dry. Cut the squash into quarters, starting at the stem and cutting through to the bottom. Then pull out each piece. (Don’t attempt to cut through the stem as it’s too dry and tough.)
Scoop out the seeds and stringy pulp with a spoon. If the quarters are very big, cut the pieces even smaller.
Place sliced pumpkin on your baking sheet (and sprinkle with salt if you want) and bake for 50-60 minutes or until the pumpkin is easily pierced with a knife in several places. You want to see the pumpkin collapse a bit under its own weight and for the flesh to pull away from the skin easily.
Allow the pumpkin to cool until you can safely handle it. Scoop out the flesh and transfer it to a food processor. (If your food processor is smaller or the pumpkin is very big, you might have to do this in batches.)
Process the pumpkin on medium-high speed until it’s very smooth, about 5 minutes.
Store fresh pumpkin puree in the refrigerator for up to 4 days. Or prepare one-cup servings in bags and freeze them for up to 6 months.