Preheat oven to 350 degrees.
Next, add walnuts to a large bowl.
In a small bowl, combine the egg white, water, and vanilla and beat together.
In a different small bowl, combine the white sugar, brown sugar, cinnamon, and salt and mix until combined.
Dump the egg white mixture over the walnuts and stir until the walnuts are coated.
Next, stir the cinnamon sugar mixture into the covered walnuts and ensure all the walnuts are coated with the mixture.
Next, add foil to a 9x13 inch pan and grease the foil.
Dump the walnuts out and onto the foil and spread the walnuts out into an even layer.
Place the pan into the oven and bake the walnuts for 15 minutes.
After 15 minutes, stir the walnuts and return to the oven.
Turn the temperature down to 300 degrees and continue to bake the walnuts, stirring every 15 minutes for 45 more minutes.
Once the walnuts are done, remove the pan from the oven and allow the walnuts to cool.
You can store cooled walnuts in a sealed container.