I prefer the recipe on the “one-pie” can. But I’m not really a pumpkin pie eater, I make if for my relatives. All I know is that the one-pie pie was very popular yesterday, and most of the leftovers went away when the guests did.
I tend to use a heavy hand with the spices. One year I foolishly bought some organic pumpkin and carefully followed the recipe on that can. No one liked it. They asked if I’d forgotten to add the spice. I hadn’t, but when I looked at the recipe, it called for less spice (and less sugar) than any other pumpkin pie recipe I’ve ever seen. The finished pie tasted like pumpkin, not like dessert. Anyway, since then I’ve made sure to add enough spice.
I’m dubious that there’s an exact scientific definition of a “pumpkin”. I think a pumpkin is the subset of winter squashes that we collective agree is pumpkin-y. The WSJ did a piece on the pumpkins that are grown for Libbys. They included a picture, and said that most Americans who came upon this fruit growing would say 'it looks like some kind of squash". Which is true, but while it is a lot longer than it is wide, and smoother and less orange than what we usually think of as “pumpkins”, it looked sorta pumpkin-y to me. And the stuff in the cans that’s labeled “pumpkin” smells more like a jack-o-lantern pumpkin than, say, like a butternut squash.
People routinely cook with the little sugar pumpkins that look like small jack-o-lantern pumpkins, but have a firmer, sweeter, less watery (and less stringy) flesh. They also smell like the stuff in the cans labeled “pumpkin” and like jack-o-lanterns, maybe even moreso than the canned stuff. Maybe that’s more “real pumpkin” than the canned pumpkin, but honestly, what it smells like (and therefore tastes like) seems more important in a canned pureed vegetable than the shape and external color of the growing gourd. And the canned stuff tastes a lot like those pumpkins.
The Journal article also mentioned that the FDA (or maybe the USDA?) promised in the 40’s that it was not going to regulate which squashes are sold as “pumpkin”