This recipe was given to my Mom from the lady who worked for my Grandpa's family when he was growing up. It's the best caramel candy in the world in my opinion. It's not always foolproof. My Mom is the only one who can make it without messing up, but I'm going to keep trying. It's worth it when it comes out right!
Bring sugar, 1 cup whipping cream, butter, and syrup to a boil. Add 1 cup whipping cream without stopping the boil. Boil to a hard ball stage (thank goodness for candy thermometers). Remove from heat. Add vanilla. Pour into a WELL GREASED pan.