Set the oven to pre-heat at 250˚F. Line a baking sheet with parchment paper and set aside.
In a medium-sized bowl, combine the granulated sugar, pumpkin pie spice and salt and stir until all ingredients are evenly mixed.
In a large-sized bowl, add the egg white, water and vanilla extract. Use a whisk or hand-held electric mixture to whip until frothy, approximately 1 minute.
Add the pecan halves to the frothy egg mixture and stir until the pecan halves are fully coated.
Pour the sugar and spice mixture over the pecans and mix until the pecans are fully coated.
Pour the pecans onto the lined baking sheet and spread out the pecans in a single layer. Place into the pre-heated oven and bake for 1 hour, stirring every 20 minutes.