In a large heavy saucepan, combine:
sugar, milk and white corn syrup, cook over medium high heat, stirring constantly.
Test by dropping into a pottery cup or bowl of cold water.
When it is at the hard ball stage, remove from heat, add vanilla, margarine and peanut butter.
Mix with a hand mixer until it starts to loose it's gloss, pour into a well buttered 9 x 13 inch pan or dish.
Let cool completely before cutting.
Not a NESTLÉ®-tested recipe.