Transfer your seeds to a colander and remove as much of the pulp and strings as possible. Rinse with cool water and continue to pick through the seeds to remove any remaining pulp. Shake the colander to drain off as much of the water as possible and pat the seeds lightly with paper towels to blot the excess water. Transfer the seeds to a 13" x 9" rimmed baking sheet.
Drizzle the olive oil over the seeds and sprinkle with garlic salt, to taste. Stir the seeds with a spatula until all of the seeds are coated with oil. Transfer the baking sheet to the preheated oven and bake for 15 to 20 minutes, or until the seeds are golden brown. Toss the seeds with a spatula once or twice during the cooking time, spreading them back out in an even layer. You may hear a pop or two and that's just fine, just continue to roast until the seeds are browned to your liking.
Remove from the oven. Taste and season with additional garlic salt, as desired. Allow the seeds to cool and then transfer them to an airtight container. Or eat them all immediately because they are DELICIOUS!
Try this recipe with other winter squash like butternut, delicata, or kabocha squash.