In a glass or metal bowl, mix together cold coffee, evaporated milk, and sugar to taste until sugar dissolves completely. Chill thoroughly.
Place 1/2 cup of vanilla ice cream in each of the bottoms of two tall glasses. Pour the chilled coffee-milk-sugar mixture over it, and top with a dollop of whipped cream.
If desired, the whipped cream can be sweetened by adding sifted confectioners’ sugar to taste but, traditionally, it is left unsweetened.
Serve immediately with an iced-tea spoon if desired. It doesn’t get any better than this.