Split the vanilla bean lengthwise and scrape out the seeds.
Add the vanilla bean seeds to the sugar and stir thoroughly to combine.
Place the vanilla bean halves on top of the sugar.
Bake the mixture for 2 hours, stirring occasionally to ensure even drying. This slow, gentle process ensures the sugar becomes completely dry and the vanilla bean turns brittle.
Remove and discard the vanilla bean halves.
Transfer the aromatic vanilla sugar to an airtight container and store it in a cool, dry place.