Preheat the oven to 350 degrees F and line a baking sheet with a piece of parchment paper and set it aside.
Combine the cashews, walnuts, almonds and pepitas in a large bowl and toss to combine.
Whisk together the egg white, water, sugar, salt, cayenne pepper and cinnamon.
Drizzle the wet mixture over the nuts and toss to combine, making sure evenly is evenly coated.
Transfer the nuts to the baking sheet and spread everything out in an even layer.
Transfer the baking sheet into the oven and roast for 30 minutes, stirring occasionally.
Remove the nuts from the oven and separate the nuts as they cool. Once they are completely cooled, transfer the nuts to an airtight container and serve as needed.