Preheat oven to 225 degrees F (105 degrees C). Lightly grease a rimmed baking pan.
Combine the egg white and water in a mixing bowl; beat until fluffy. Fold in the pecans to coat evenly. Combine the sugar, salt, and ground cinnamon in a shaker or cup with a lid. Dust the pecans evenly with the sugar mixture. Spread the nuts over the prepared pan.
Bake in preheated oven until toasted and fragrant, stirring every 15 minutes, about 1 hour. Cool on pan, and store in an airtight container.