1. Preheat oven to 250°. Stir together first 4 ingredients in a small bowl. Whisk egg whites in a large bowl until foamy. Add pecans, tossing to coat. Add spice mixture, tossing to coat.
2. Spread nut mixture in a single layer on a parchment paper-lined baking sheet.
3. Bake at 250° for 1 hour, stirring after 30 minutes. Let cool slightly, and break pecans apart. Cool to room temperature. Store in an airtight container up to 2 weeks.
We tested with J & D's hickory-flavored bacon salt and crushed chipotle chile and smoked serrano chile powder from Williams-Sonoma.