Preheat the oven to 180 degrees Celsius. Grease and line a 7inch tin leaving some parchment hanging over the edges (to help lift the slice out of the tin).
Whisk the egg whites until stiff. Fold in the flour followed by the almonds and icing sugar. Spoon the mixture into the tin and press down firmly over the base of the tin. Bake for 10-12 minutes or until golden. Leave to cool.
Dust with lots of cocoa and ground cinnamon to taste and cut into little squares as needed.
