01 - In a large mixing bowl, blend finely ground almonds, powdered sugar, ground cinnamon, and salt until evenly combined.
02 - In a separate bowl, whisk egg whites until stiff peaks form. Gently incorporate vanilla extract and lemon juice.
03 - Fold the whipped egg white mixture into the dry ingredients, mixing gently until a sticky dough is achieved.
04 - Wrap the dough in plastic wrap and refrigerate for at least 1 hour, or until firm.
05 - Preheat oven to 325°F. Line baking sheets with parchment paper.
06 - Roll out chilled dough between two sheets of parchment to approximately 1/2 inch thickness. Use a star-shaped cookie cutter to cut dough and arrange stars on prepared baking sheets.
07 - In a clean bowl, whisk the egg white until frothy. Gradually beat in powdered sugar and lemon juice until a thick, glossy icing develops.
08 - With a pastry brush, spread a thin, even layer of icing onto each star-shaped cookie.
09 - Bake in preheated oven for 10 to 12 minutes, until icing sets and cookies are firm but remain pale.
10 - Transfer cookies to a wire rack and allow to cool completely before serving or decorating further.