Grind almonds in a food processor until they’re fine. Grate or grind the chocolate. Mix the chocolate, almonds, and sugar. Add the cinnamon if desired. Beat egg whites until stiff, not dry, peaks are formed. Mix into the chocolate mixture along with the almond extract or Kirsch. Chill thoroughly.
Roll out a portion at a time to 1/4-inch thick or a little thicker, using more sugar to keep dough from sticking. Cut into shapes, but not too big. Place on lightly greased cookie sheet, or use a silpat or parchment paper. Scraps can be pressed together and re-rolled.
Bake at 350 degrees F for 13-14 minutes. Cool a few minutes before carefully placing on a rack to cool completely.