Preheat oven to 250 degrees F. Grease a baking sheet with melted butter. Set aside.
In a mixing bowl, whisk together the egg white, water and vanilla until frothy. Add the pecans to the egg white mixture and, using a rubber spatula, stir until the pecans are completely coated.
In a separate bowl, mix together sugar, salt and cinnamon. Pour half of the sugar mixture over pecans and toss several times, then add remaining sugar mixture and toss until evenly coated. Spread the nuts on the prepared baking sheet in a single layer.
Bake for 1 hour, stirring them every 15 minutes. Remove from the oven and cool to room temperature. Store in an airtight container. Enjoy!