Grease or line an 8 inch baking dish with parchment paper.

Combine all ingredients in a large saucepan over medium heat. Stir constantly until mixture reaches 245º F on a candy thermometer. If you don't have a thermometer; test in a cup of cold water. Drop a small amount into water, and shape into a ball. Once it holds is shape until pressed, it is done.

Remove the pan from the heat immediately and stir in the vanilla extract.

Pour into prepared baking dish, and allow to cool completely.

Cut into 1 inch squares, and wrap individual in plastic wrap, foil, or wax paper.