Line a 10x15x1 jelly roll pan with non-stick foil and set aside.

Combine corn syrup, brown sugar, butter, and sweetened condensed milk in a large (at least 6 quart) nonstick heavy bottomed saucepan. Cook stirring constantly over medium heat until the mixture reaches between soft and firm ball stage (about 250 F).

Remove from heat and add vanilla.

Pour into prepared pan and let cool completely.

Cut and wrap in confectioners' waxed twisting paper.