1 sugar cube
2 fluid ounces absinthe
4 fluid ounces cold water, or to taste
Place sugar cube on an absinthe spoon or in small strainer set over a glass. Pour absinthe over sugar cube into the glass.
Light the sugar cube on fire and allow sugar to caramelize for 10 to 15 seconds. Slowly pour water over sugar cube until it dissolves and the drink begins to turn opaque. Stir to combine.