Wash your pie pumpkin or squash and cut off the top stem. Depending on the size of it, you can either leave it whole (if it's small) and scoop out the seeds from inside, or cut it in half and remove the stringy pulp and seeds from each half.
Place each pumpkin half cut-side down on a parchment lined baking tray. Bake for 45 to 60 minutes, until the skin has started to become golden and you can pierce the flesh with a sharp knife with no resistance. Let the pumpkin cool until it's just warm enough to handle without burning yourself.
Depending on the type of pumpkin/squash you use, the skin should peel off quite easily (this is especially true for pie pumpkins). If the skin fragments into little pieces, then you can use a spoon and carefully scoop out the soft flesh. This is definitely recommended for kabocha and hubbarb squash as the skins tend to be thicker and less peelable.
Place the cooked pumpkin flesh in the bowl of a food processor or blender. Blend it until a nice smooth, creamy and thick purée has formed. Transfer to sealable jars or containers and store in the fridge for up to 10 days or in the freezer for months.
