Heat oven to 300 degrees. Whisk egg white in a small mixing bowl until slightly frothy. Add pecans and whisked egg white to a large mixing bowl. Stir to evenly coat pecans.
Add white sugar, brown sugar, ground cinnamon and salt. Stir again until evenly coated.
Transfer pecans to a baking pan lined with parchment paper. Spread into a thin, even layer. Bake for 40 minutes, stirring halfway through. Let cool before serving.
Notes
The secret to evenly candied pecans is a mid-bake stir. Bake them for 20 minutes, give them a good stir to redistribute the sugary coating, then return them to the oven for another 20 minutes. Let them cool completely before adding them to the spread.