Cut the pumpkin in half and remove seeds and strings.
Place the pumpkins cut side down on a baking sheet. Add about half a cup of water.
Bake in a 375 degree oven for 30 to 60 minutes or until pumpkins are soft.
Let cooked pumpkins cool about 10 minutes or until it can easily be handled.
Peel the skin off the pumpkin, then break the cooked pumpkin into pieces.
Place cooked pumpkin pieces into a bowl and with a hand blender, blend the pumpkin into a smooth puree.
Store prepared pumpkin puree in an airtight container in the refrigerator up to a week or for longer storage freeze it.
Notes
If you don't have an immersion blender you can add the cooked pumpkin puree to a food processor and process until smooth.Or you can use a potato masher to break up the pumpkin into puree.