Pour 2 cups of granulated sugar into a clean, dry, airtight jar. Use a sharp knife to cut the vanilla bean in half lengthwise and carefully scrape out the seeds.
Add the vanilla seeds to the sugar. Place the scraped vanilla pod into the jar with the sugar for added flavor.
Seal the jar tightly and give it a gentle shake to mix. For best flavor, let the mixture infuse at room temperature for at least 2 weeks, shaking the jar every few days.