Iced Cappuccino

Directions

1. 1
   Whisk together first 4 ingredients in a large saucepan until smooth. Bring to a boil over medium heat, whisking constantly; boil, whisking constantly, 2 minutes.
2. 2
   Remove from heat. Cool slightly.
3. 3
   Stir in 6 cups cold milk, vanilla, and, if desired, liqueur. Cover mixture, and chill up to 2 days, or pour each serving immediately over 1/4 cup ice cream or ice cubes.
4. 4
   Garnish, if desired.