2 3-pound sugar pumpkins, also called baking pumpkins (total 6 pounds)
Thoroughly wash the outside of the pumpkin to remove any loose soil or blemishes.
Remove stem and seeds and cut the pumpkin into six or eight pieces, depending on size. Leave skin on.
Snug into a six-quart slow cooker and set timer to six hours on low.
Once done, cool slightly to make it easy to handle and take each piece out and run a spoon between flesh and skin, discarding skin. Place flesh into a large bowl. (We discarded the skin, but some recipes purée the skin in with the flesh. Your choice.)
Using an immersion blender purée until smooth. You could also use a blender or food processor however may need to purée in batches.
Place in quart zipper seal bags and freeze until needed, or use immediately.