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.