Preheat the oven to 275˚. Line a large baking sheet with parchment paper or aluminum foil and mist with nonstick oil spray. Set aside.

In a large bowl, combine the egg white and vanilla and whip until very frothy. Add the almonds to the bowl and stir until they are completely soaked in egg white, about 2 minutes.

In a small bowl, stir together the sugar, cocoa powder and salt until thoroughly mixed. Add the sugar-cocoa mixture to the almonds, and stir until the dry ingredients are completely incorporated and almonds are evenly coated (no dry powder should remain at the bottom of the bowl).

Pour the almonds onto the prepared baking sheet and use a spatula, spoon or your hands to spread them in a single even layer. Bake for 25 minutes on the middle oven rack.

Cool for at least 15 minutes. Break the almonds apart before serving. Store in an airtight container.