Preheat oven to 350 degrees. Cut each pumpkin in half with a sharp knife and clean out the middle part (the pumpkin guts and pumpkin seeds). Spread the inner pumpkin with some butter or oil and sprinkle with salt.

Line a cookie sheet with aluminum foil or parchment paper. Place the pumpkin halves face down on the prepared baking sheet (outer shell side up).

Bake for 30 minutes or until fork tender. Once pumpkin is easily pierced with a fork, remove from the oven and allow to cool at room temperature.

Remove the inner pumpkin (flesh) from the pumpkin shell and place it in a large mixing bowl.

Using an immersion blender or food processor, purée the pumpkin until smooth.

Measure the puréed pumpkin into 2 cup portions and add to freezer bags. Flatten and stack baggies for easy freezing.