Preheat The Oven & Prep Your Pan. Start by preheating the oven to 250 degrees F. Set out a cookie sheet/sheet pan for later. (Don't line it with parchment or foil--it interferes with the dehydrating process).

Combine The Cinnamon Sugar Mixture. In a small bowl, combine sugar, cinnamon, and salt. Whisk or stir until very well blended and set aside.

Froth The Egg White And Vanilla. In a large mixing bowl, combine egg white and vanilla. Use a hand mixer to beat the egg white 1-2 minutes, or until just frothy. This works with a whisk, too, it'll just take longer. You don't want it super liquid (not enough beating) and you don't want to whip it to stiff peaks (too much beating!)

Coat The Pecans. Add pecans to the frothy egg white mixture and stir to coat. Sprinkle with cinnamon-sugar mixture and stir again, until all pecans are well coated.

Bake The Pecans. Spread the cinnamon sugar pecans out into an even layer on your prepared baking sheet. Roast in the preheated oven at 250 degrees F. for 1 hour, stirring every 15 minutes. (Bake the full time, or the cinnamon-sugar coating won't be as dry and crisp as you need.)

Cool Completely. Remove the pecans from the oven and cool completely on the baking sheet before storing.

Serve Or Store. Store cooled cinnamon pecans in an airtight container, jar, or bag at room temperature 2 weeks, or freeze in a freezer bag for 1 month.