Preheat the oven to 325°F (165°C) and line a baking sheet with parchment paper. Set aside.
In a medium bowl, mix together the sugar, egg whites, butter, vanilla extract and salt until blended.
Whisk in the flour until smooth and lump free then fold in the almonds.
Pour the batter onto the prepared baking sheet. Spread the batter out as thinly as possible and bake for 30 - 40 minutes or until golden brown all over.
Remove from the oven and allow to cool for 30 minutes to firm and crisp.
Break up the cookie into pieces and enjoy! Store cookies in an airtight container at room temperature for up to 3 days.