Summarize:

Lining your baking sheet with parchment paper will prevent the seeds from sticking the best, though you can also use aluminum foil. Once the oven is preheated, you're ready to roast your seeds. Pour the seasoned pumpkin seeds onto the lined baking sheet, using a spoon to spread them out. Try to make sure they aren’t clumped together and are laying flat so they roast evenly. If your pumpkin seeds end up layered on top of one another, try baking them in two smaller batches to promote even roasting. Remove the baking sheet from the oven every 10 minutes and move the seeds around using a wooden spoon or other kitchen utensil—this will help ensure each seed roasts evenly. Once the seeds look browned, they’re done! Once the seeds have been removed and the oven is turned off, use a spatula to scoop the seeds into a bowl or other serving dish. You can eat them while they’re still warm from the oven, or let them sit for a few minutes until they’re cool. If you want to save your roasted pumpkin seeds, put them in an airtight container such as a mason jar, plastic bag, or piece of tupperware. The seeds will stay fresh for a week or so at room temperature, or you can place them in the freezer for up to a month.  If placing the seeds in the freezer, they should be in an airtight container as well. Write the date on the container so you remember when the seeds were roasted.
Preheat the oven to 350 °F (177 °C) and prepare a sheet pan. Spread the seeds out evenly on the baking sheet. Bake the seeds for 20-30 minutes, stirring them occasionally. Eat the seeds warm or let them cool to room temperature. Store the seeds in an airtight container for roughly 1 week.