Preheat the oven to 250 degrees F (120 degrees C). Grease a baking sheet with cooking spray.
Whisk together egg white and water in a medium bowl until frothy. Mix together sugar, salt, and cinnamon in a separate bowl.
Add pecans to egg white mixture; stir to coat. Transfer pecans to sugar mixture; toss to coat. Spread pecans out on the prepared baking sheet.
Bake in the preheated oven until crisp, about 1 hour; stir every 15 minutes.
