Start by cutting open your pumpkin and scooping out all the seeds and stringy pulp. This is the messy part, but kids usually love helping with this step! Once you've got everything out, place the seeds in a strainer and rinse them under cool water while picking out any remaining pumpkin strings.
Pat the seeds completely dry with paper towels. This step matters because wet seeds won't get as crispy in the oven. Toss the dried seeds in a bowl with the vegetable oil and salt until every seed is lightly coated.
Line a 9x13 baking sheet with parchment paper and spread the seeds in a single layer. Make sure none of the seeds overlap, as this helps them bake evenly. Bake at 350 degrees Fahrenheit for about 15 minutes, checking occasionally, until the seeds are golden and crunchy but not overly browned.
Notes
Dry Seeds Thoroughly - The drier your seeds are before roasting, the crunchier they'll become. Let them sit on paper towels for 10-15 minutes if you have time.
Don't Overcrowd the Pan - If your seeds overlap, they'll steam instead of bake properly. Use two pans if needed to give each seed its own space.
Watch the Temperature - Cooking at 350 degrees gives you the best results for oven baked pumpkin seeds. Higher temperatures will brown the outside before the inside gets crunchy.
Check Often - Pumpkin seeds can go from perfectly roasted to burnt quickly. Start checking at the 12-minute mark and shake the pan once or twice during baking.
Seed Yield Varies - Every pumpkin is different, so you might get more or less than ¾ cup depending on your pumpkin's size and variety.