Stir together the almonds, cinnamon and lemon zest until combined.
Beat the egg whites and salt until soft peaks form. Slowly sift in the icing sugar, continuing to beat until the mixture is stiff. Set aside 1/3 cup of the egg white mixture for the glaze. Fold in the almond mixture.
Preheat oven to 170 degrees C. Line the baking trays with baking paper.
Roll the dough to 6mm thickness on a surface that has been sprinkled with icing sugar. Using a 6cm star cookie cutter, cut out the biscuits and place them on the baking trays.
To make the glaze, add the lemon juice to the reserved egg white mixture, stirring until smooth. Brush the tops of the biscuits lightly with the glaze. (If the glaze starts to thicken, add a few more drops of lemon juice.)
Bake for 20 to 25 minutes. When done, they will be light brown and soft in the centre. Remove and cool on wire racks.