Place the steamer rack trivet in your Instant Pot, then add 1 cup of water and place the whole baking pumpkin on the rack. Seal the lid, then cook on high pressure for 15 minutes. 

Once the timer goes off, release the pressure manually, then remove the pumpkin from the pot and let it cool for about 15 minutes, until it’s at handling temperature.

Using a sharp knife, cut the pumpkin in half, starting near the stem and making your way through the pumpkin. Once split, use a spoon to scrape out the seeds. 

Flip the pumpkin halves over so that the shell side is up, then peel off the skin. If the skin isn't breaking apart easily, you can scoop the flesh out instead.

Transfer the pumpkin flesh to a food processor, then puree for 3-5 minutes, until smooth.

Store the pumpkin puree in airtight containers for a week in the fridge or up to 4-5 months in the freezer.