Tip: To harvest seeds from a spaghetti squash, scoop out the inside of the squash. Separate the seeds from the flesh as well as you can, then place the seeds in a bowl of water. Use your hands to swish the seeds around to loosen any remaining flesh or strings. The seeds will float, so you can remove them with a spoon or your fingers. Drain the seeds on a dry dish towel or a plate lined with paper towels; pat dry with paper towels.
To make ahead: Store in an airtight container for up to 3 days.