Using a large spoon or ice cream scoop, remove the pulp inside the pumpkin. Disentangle the raw seeds from the stringy fibers. The number of seeds will depend on the size of the pumpkin.
Put the seeds in a large bowl of cool water and use your hands to separate the seeds from the pulp. The seeds will float to the top once they’ve been separated from the pulp.
Put the separated seeds in a colander to drain as you work. It might take a little time, but try to remove as much pulp from the seeds as you can.
Spread the separated seeds on a piece of parchment paper or kitchen towel to air dry (don’t use paper towels—the seeds will stick to them as they dry). The seeds don’t have to be completely dry before roasting, but this process help crisps the seeds faster during roasting.
Toss the dry seeds in a large bowl with a little olive oil and season to taste using savoring or sweet seasoning(s) of choice. Go easy on the more potent seasonings to start, especially the salt. It is very easy to over-salt the seeds before roasting, so add just a little bit at a time. I always say it is better to under-salt than over-salt because you can always add some later if needed, but you sure can’t take it back once its in there.
Spread the seasoned seeds out in a single layer on a large nonstick cookie sheet (you can also line the tray with parchment paper). Roast the seeds in the oven for 12 to 30 minutes (or longer, depending on how dry (or wet) they were to start) at 350°F (177oC). Check the seeds often to avoid over-roasting them, and toss them a few times during the cook cycle for even cooking and browning. When the seeds are a golden brown color and crunchy, they are ready!
Once they’ve completely cooled, roasted pumpkin seeds can be stored in an airtight container—up to 7 days at room temperature and for 2 to 3 weeks in the fridge.