Preheat the oven to 250 degrees F. Line a baking sheet with parchment paper.
In a medium bowl, combine the sugar, cinnamon and salt. Stir to mix.
In a large bowl, whisk the egg whites, water, and vanilla. Add pecans and toss evenly to coat. Pour sugar mixture over pecans and stir to coat. Spread pecans on baking sheet and cook for one hour, stirring them every 15 minutes. Remove from oven and cool to room temperature.
Notes
Storing: Cooked and cooled caramelized pecans can be stored in an airtight container or sealed jar for up to 2 weeks. Fridge storage can extend the freshness of the pecans for up to 6 months. Freezing: To freeze, add cooked and cooled sugared pecans to an airtight container or sealed freezer-safe bag. Remove as much air as possible and store for up to 4 months. Spread them out on a sheet pan to thaw completely.