Finely grind nuts in food processor. Add honey, egg white, cocoa, spices and salt. Blend to paste. Add flour and mix using on/off turns until just incorporated. (NOTE: Dough will be sticky.)
Place dough on work surface heavily dusted with sifted confectioners' sugar. Sift more powdered sugar over dough. Gently roll dough out to thickness of 3/8". Cut into 1x1 1/2 inch bars using knife that has been dusted with powdered sugar. Arrange on greased sheet, spacing 1inch apart.
Bake cookies at 275 F (135 degrees C) until firm and tops appear dry, about 25-30 minutes. Cool cookies completely on racks.
To Make Icing: Blend 1/2 cup confectioners' sugar and 2 teaspoons egg white. Mix in enough liqueur to make thick but pourable icing. Set racks on waxes paper; arrange cooled cookies on racks with edges touching. Drizzle icing over cookies in irregular lines. Separate cookies. Let stand until icing is dry. Store in airtight container.