Preheat the oven to 350 degrees Fahrenheit
In a large sauce pan over medium heat, combine the water and sugar and stir until the sugar is dissolved then stir in the walnuts and bring to a boil.
In a separate bowl, combine the sesame seeds, cayenne and salt and set aside.
Once the mixture is boiling, stir in the sesame, cayenne, and salt and stir until the water is mostly evaporated. Lower the heat and continue to stir until the walnuts are golden brown and sandy, around 4 minutes.
Line a baking sheet with parchment paper
Pour the walnuts onto the baking sheet and spread into a single layer.
Bake for 20 minutes until the nuts are golden brown with a sandy coating
Remove from the oven and let cool completely in the pan.
Break up any clusters and transfer to a bowl to serve.