1/2 cup light Karo corn syrup
1 cup granulated sugar
1 water
3 (1-oz) squares unsweetened chocolate
1 cup evaporated milk
1 tsp vanilla extract
In a large saucepan, combine the corn syrup, sugar, and water and cook until it reaches the soft ball stage (236 degrees). Remove from heat and stir in the unsweetened chocolate, stirring until the chocolate has melted. Slowly stir in the evaporated milk and vanilla. Stir well. Let cool thoroughly and then store in the refrigerator. Serve warmed or cold over ice cream.