Process almonds and confectioners' sugar in a food processor until almonds are finely ground. Add chocolate, 1/4 cup sugar, cocoa, cinnamon and salt. Process until chocolate is finely ground. Add egg whites and vanilla, pulse until dough forms. Transfer dough to parchment paper and knead to form a smooth ball. Chill for 10 minutes until no longer sticky. Preheat oven to 325 ℉. Roll dough to 1/4 inch thickness between two sheets of parchment paper. Spread 1/2 cup sugar in shallow bowl. Cut into stars and dip to coat both sides with sugar. Place stars on parchment lined cookie sheet or silicon baking mat. Bake for 12-15 minutes, cool on pan for 15 minutes and then move to cooling rack.
NotesEgg yolks can be used to make egg yolk lemon cookies.