In saucepan, combine sugar, lemon rind, star anise, cloves, cinnamon stick, and water; bring to boil, stirring to dissolve sugar. Remove from heat. Pour in coffee; let stand for 10 minutes. Strain through fine sieve into bowl; refrigerate until chilled completely.
Stir in liqueur. Pour into metal cake pan. Freeze for 1 hour. Stir with fork; repeat every 30 minutes until mixture forms small, even crystals. Serve immediately.