Preheat the oven to 160ÂșC and line a baking sheet with parchment paper.
In a bowl, combine the ground almonds, cinnamon and sugar.
In another bowl, beat the egg whites until firm, then gradually fold it into the almond mixture.
Add the vanilla extract and stir until you have a smooth batter.
Spoon about 21 dollops of mixture onto the baking sheet, allowing enough space for them to expand.
Bake for about 10-15 minutes until the cookies look golden and are cooked through.
Let them cool for a couple of minutes, then move them to a cooling rack.
Mix some icing sugar with cinnamon and dust the cookies just before serving.