Once they have a taste, they'll ask for the recipe!
Line an 8 inch square pan with foil; grease the foil with 1 teaspoon butter and set aside.
In a large heavy saucepan, combine sugar, corn syrup and remaining butter; bring to a boil over medium heat, stirring constantly.
Boil slowly for 4 minutes without stirring.
Remove from the heat; stir in milk.
Reduce heat to medium-low and cook until a candy thermometer reads 238° (soft-ball stage), stirring constantly.
Remove from the heat; stir in vanilla.
Pour into prepared pan (do not scrape saucepan). Cool.
Using foil, lift candy out of pan.
Discard foil; cut candy into 1 inch squares.
Wrap individually in waxed paper; twist ends.