Simple syrup, to sweeten (Equal parts sugar and water brought to a boil and stirred until the sugar is dissolved, then cooled)
Coffee-flavored liqueur, to taste (recommended: Kahlua)
Chicory coffee ice cubes (Make with leftover cooled coffee and freeze in an ice cube tray)
Put 2 cups cooled coffee, 1/4 cup half-and-half, simple syrup, to taste, a few shots of coffee-flavored liqueur and a few cubes of the chicory coffee ice cubes in a blender and blend until smooth and icy. Pour into tall glasses. Repeat.