Preheat the oven to 350°F. Line a baking sheet with a piece of parchment paper and set 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 and chipotle pepper and cinnamon. Drizzle mixture over the nuts and toss to combine, making sure they are evenly coated. Transfer nuts to prepared baking sheet and spread in an even layer. Roast in oven for 30 minutes, stirring occasionally. Remove from oven; separate the nuts as they cool. Once they are completely cooled, transfer to an airtight container.