1Preheat oven to 200 degrees F (95 degrees C). Prepare a jelly roll pan with cooking spray.
2Beat egg white and sugar together in a large bowl.
3Mix cinnamon, vanilla extract, and salt together in a small bowl; stir into the egg mixture. Fold walnuts into the mixture to coat; spread onto prepared jelly roll pan.
4Bake in preheated oven until the coating on the nuts is crusty, about 1 hour 15 minutes. Cool nuts 5 minutes before serving.