In a small bowl, whisk together the Redpath® Dark Brown Sugar, Redpath® Special Fine Granulated Sugar, salt, cinnamon, paprika, and cayenne pepper, if using, until well combined.
In a large bowl, whisk the egg white and water together until frothy. Add almonds and pecans to the bowl and stir until nuts are evenly coated with the egg white mixture.
Sprinkle the sugar-spice mixture over the nuts. Toss to coat evenly.
Preheat the air fryer to 325°F (163°C) according to the manufacturer’s directions. Line the bottom of the air fryer basket with parchment paper, being careful of the hot sides.
Depending on the size of the air fryer, work in batches. Place about a third to half of the nuts into the lined basket. Bake for 10 minutes.
Remove and shake the basket and flip the nuts over using a heatproof rubber spatula or wooden spoon. Bake for an additional 5 to 8 minutes or until the nuts are fragrant and the topping has dried.
Carefully remove nuts from the basket and spread onto a parchment-lined baking sheet to crisp up and cool completely; 10 minutes. Repeat process until all nuts have been air fried.
Once nuts are cooled, break apart any that may have fused together. Store in an airtight container for up to 3 weeks at room temperature.