Preheat oven to 250 degrees and grease a large baking sheet.

Combine sugar, salt, cinnamon, and ginger in a small bowl. Set aside.

In a large bowl, whip the egg white and vanilla until it gets frothy, about 1 minute.

Add the hazelnuts to the egg mixture and stir until they're evenly coated.

Pour the dry mixture over the hazelnuts and mix together until they're evenly coated.

Spread the hazelnuts into an even layer on the baking sheet.

Bake for 1 hour, stirring every 15 minutes.

Remove the hazelnuts, stir once more, then allow to cool.

Store in an airtight container for up to 2 weeks, or in the freezer for up to 3 months.