In medium double boiler, cook sugar, cornstarch, milk and salt. When mixture begins to thicken, add part of mixture to egg yolks; mix well, then pour egg mixture back into mixture in double boiler.
Cook until thick; take off stove, then add butter and vanilla.
You can use as pudding and top with Cool Whip or use pudding with bananas for banana pudding You can also add 2 unsweetened chocolate squares at the beginning and make a chocolate pie or pudding.
For butterscotch pie or pudding, use 3/4 cup light brown sugar firmly packed and 1/4 cup sugar instead of 3/4 cup sugar, then cook as directed.
You can also make a banana plate pie with the vanilla mixture, just cook as directed.
In baked pie shell, line bottom with bananas; pour a layer of pudding, then a layer of ba nanas, then pudding.
You can top with Cool Whip or meringue.