Preheat oven to 300 degrees F. and line a baking sheet with parchment paper.
In a large bowl, whisk the egg white until frothy. Stir in sweetener, cinnamon, vanilla extract, and salt. Add the almonds and stir until fully coated.
Spread the almonds in a single layer on the baking sheet. Bake for 25-30 minutes, stirring halfway through.
Let the almonds cool completely, they'll get crunchier as they cool.
Store in an airtight container for up to 2 weeks.