What they don't require is a trip to the grocery store to buy pumpkin puree. All you need is a pumpkin, an oven, and a blender. I rescued this pumpkin that never got carved into a Jack O Lantern.
I cut it in half. And for extra flavor, let a baby gnaw on it.
I scooped out the seeds and the gunk (and saved the seeds to make roasted pumpkin seeds with later!) Then cut it into pieces like this and put it on cookie sheets and baked it at 350 for 45 minutes. I filled these 2 cookie sheets twice with this sized pumpkin. Some people line their cookie sheets with foil, but this really doesn't make that much mess, and I'd rather scrub off the cookie sheets than have to buy more aluminum foil.
Not only do you save quite a bit doing it this way (especially if you grew your own pumpkins, which are very low maintenance and easy to grow), but the taste is 100 times better than canned.