Chill the absinthe glass, a spoon and the absinthe in the freezer for at least four hours. Chill water in refrigerator.
Set the spoon upon the chilled absinthe glass. Place the sugar cubes on the spoon. Pour absinthe over the sugar cubes. Pour chilled water over sugar cubes. Pour sour mix over remainder of sugar cubes. If any sugar is left on spoon, dump it into the glass and stir.