Preheat oven to 250°F.

In a small bowl, mix sugar, cinnamon, red pepper (if using), and salt.

Set the spice mixture aside.

In a medium bowl, beat egg white and vanilla until foamy.

Add nuts to the egg white mixture and stir to coat.

Add the spice mixture to the nuts and toss to coat evenly.

Spread the nuts in a single layer on a lightly greased baking sheet.

Bake in the preheated oven for 1 hour, stirring after 30 minutes.

Cool slightly and break apart.

Cool completely.

Store in an airtight container for up to 2 weeks.