Preheat the oven to 300°F (150°C).
Place the cleaned seeds in a colander and rinse under cold water to remove any remaining pulp.
Pat the seeds completely dry with a clean kitchen towel; moisture is the enemy of crispness.
In a medium mixing bowl, combine the dried seeds, olive oil, salt, and garlic powder.
Toss the mixture until all seeds are evenly coated with the oil and seasonings.
Spread the seeds in a single layer on a rimmed baking sheet lined with parchment paper.
Bake for 45 minutes, stirring the seeds every 15 minutes to ensure even browning.
Remove from the oven when the seeds are golden brown and allow to cool completely on the tray to finish the crisping process.