Start with the disappointing part: the pumpkin you carved is mostly not worth eating. Carving pumpkins are field varieties selected for size and a hollow cavity, with stringy watery flesh and little flavor. A jack o lantern that sat on a porch for a week, handled with unwashed hands and open to insects, is also a food safety problem rather than an ingredient. Compost that one.
Canned pumpkin puree is a different product, usually a Dickinson type squash, and nutritionally it is one of the better things in a pantry. USDA data for one cup, 245 g, of canned pumpkin without salt: 83 calories, 7.1 g of fiber, 2.7 g of protein, 206 mg of potassium, and 778 mcg RAE of vitamin A.
That vitamin A figure is the standout. The daily reference intake for adult women is 700 mcg RAE, so a single cup covers about 111 percent, or roughly 86 percent of the 900 mcg reference for men. The 7 g of fiber is about a quarter of the daily reference for 83 calories, which is a rare ratio in any food.
check the label before you buy
Two products sit next to each other on the shelf and they are not the same thing. Canned pumpkin puree has one ingredient. Canned pumpkin pie filling has added sugar and spices, and typically lands somewhere near 180 to 200 calories per half cup against 40 for plain puree.
Watch sodium too. The salted version of canned pumpkin runs about 590 mg of sodium per cup against roughly 12 mg for the unsalted. That is a quarter of the 2,300 mg daily limit from a single ingredient, which matters if you are building a soup that also contains broth.
uses that hold up
Soup is the obvious one and it works because pumpkin puree thickens without flour. A base of onion, garlic, one cup of puree, two cups of low sodium broth, and half a cup of coconut milk produces something substantial in 15 minutes. Adding pumpkin to a lentil recipe, as the old version of this advice suggested, is genuinely good: the lentils supply protein and the pumpkin supplies fiber and body.
Blended into a drink it works well, mostly for texture. A quarter cup of puree with a banana, a cup of almond milk, a tablespoon of ground flaxseed, and cinnamon gives you roughly 200 calories with about 7 g of fiber. The flaxseed is where the omega 3 comes from, not the pumpkin, and one tablespoon of ground flax supplies roughly 1.6 g of alpha linolenic acid, which covers the 1.1 g daily reference for adult women on its own.
One correction to that recipe as usually written: with no protein source it is not a meal, and blended fruit with no protein empties from the stomach fast. A scoop of whey or 150 g of Greek yogurt turns it from a snack into something that holds until the next meal.
Stirring a few tablespoons into oatmeal or plain yogurt is the lowest effort use and the one most likely to actually happen on a Tuesday.
Roasting the seeds is worth more than most of the pulp. Pumpkin seeds carry roughly 7 g of protein per ounce and are one of the better plant magnesium sources, at about 150 mg per ounce against a 310 to 320 mg daily reference for adult women. Rinse, dry thoroughly, toss with a little oil and salt, and roast at 300 F for 40 to 45 minutes, stirring twice. The lower temperature matters: at 400 F the outside burns before the inside crisps.
the cosmetic uses, honestly
Pumpkin face masks and hair masks appear in every seasonal list, and the reasoning given is usually that the vitamin A, vitamin C, and zinc in pumpkin nourish skin.
That reasoning does not survive contact with how skin works. Nutrients in food are absorbed through your gut, and topically applied vitamin A from a vegetable puree is not the same molecule or concentration as the retinoids that have actual clinical evidence for skin. Vitamin C in a puree is unstable and at an unknown concentration and pH, which are the two variables that determine whether topical vitamin C does anything.
The honest version: a pumpkin and honey mask is a pleasant thing to put on your face for 15 minutes. Honey is mildly humectant, the puree is mildly acidic and contains enzymes that can have a very light exfoliating effect, and the whole experience is nicer than the ingredient list justifies. Do not expect the vitamin content to do anything, and skip it entirely if you have irritable skin, because plant enzymes on compromised skin can sting.
The coconut oil hair mask works, and the pumpkin is along for the ride. Coconut oil has decent published evidence for reducing protein loss in hair, which is a real mechanism. Three tablespoons of coconut oil would do the same job without the cup of pumpkin, and would wash out more easily.
what to do with the shell
Composting is the best answer for a carved pumpkin, and it is the one use with no caveats. Pumpkins are around 90 percent water and break down quickly. Remove any candle wax and pull out the seeds first unless you want volunteer vines next summer, which some people do.
The bird feeder idea works but has a timing constraint nobody mentions. A cut pumpkin left outside starts to rot within days depending on temperature, and moldy feeders are bad for birds. If overnight lows are above freezing, give it three or four days and then compost it.
Using a small pumpkin as a soup bowl works if you bake it first, roughly 30 to 40 minutes at 375 F until the flesh is tender, then fill it. Filling a raw pumpkin with hot soup gives you soup with a raw pumpkin around it.
Saving seeds for next spring is fine if the pumpkin was an heirloom variety. Most supermarket pumpkins are hybrids, and hybrid seed does not reliably produce the parent plant. You will get a pumpkin of some kind. It may not be the one you wanted.