(Yet another Old Family Recipe)
Combine sugar, flour, cornstarch, and salt in top of double boiler, mixing thoroughly.
Add milk gradually, stirring well.
Place over boiling water; cook and stir until thickened (wire whisk meets distinct resistance from the liquid). After thickening has occurred, cook 10 minutes longer, stirring occasionally.
Take off heat; add vanilla.
Chill (if the howling hordes will let you); serve with optional milk or cream. It’s only fair to note that — at least at our house — the pudding is seldom around long enough for anyone to serve it thoroughly chilled.
(Note: Peppermint extract also works. So will various liqueurs, such as Frangelico.)