Finely ground your almonds or pecans and place in a bowl.
Quickly ground regular white granulated sugar to make caster sugar and put with ground nuts. Add flour, cinnamon and egg. Mix until blended and smooth.
Wrap in plastic and set in refrigerator for at least 2 hours. Roll dough between two sheets of parchment paper to ¼ inch thickness.
Cut cookies with a star shaped cookie cutter and place on baking sheet with parchment paper.
Spread meringue glaze over each cookie and bake at 325 °F for 10 minutes.
Lift entire parchment paper with cookies on it onto wire rack to completely cool before touching.
Meringue Glaze
Whisk egg whites and powdered sugar together on high speed.
Whisk glaze together until you make a thick mixture that does not run. It must not run or drip off a butter knife.