Preheat oven to 250F. Cover a baking sheet with parchment paper.
In a bowl, combine sugar, pumpkin pie spice and salt. In a separate bowl, beat egg white and vanilla until foamy. Add the pecans and toss to coat. Add the spice mixture and stir to coat.
Spread pecans in a single layer on the prepared baking sheet. Bake for 1 hour, stirring once. Cool and break apart. Can be stored up to 2 weeks in an airtight container.