Preheat oven to 250 degrees F. Grease a large baking sheet. (Do NOT use parchment paper or foil. Bake directly on the greased pan)!
In a large mixing bowl, whip egg white and vanilla with a whisk until frothy.
In a separate bowl, combine sugar, salt, and cinnamon, set aside.
Add pecans to wet mixture 1 cup at a time, stirring to coat the nuts evenly. Depending on the size of your egg white you may use slightly more or less than 4 cups pecans. Just make sure all nuts are well coated before adding more.
Once pecans are completely coated, add in the dry ingredients and mix until the nuts are evenly coated.
Spread the pecans evenly on the prepared baking sheet.
Bake at 250 degrees F for 1 hour. Stir every 15 minutes (you will stir 3 times before removing from the oven).
Smell the air and try not to burn your mouth eating them straight from the oven!