1 c. light Karo syrup
2 c. confectioners' sugar
1/3 c. Hershey's cocoa
1/2 c. boiling water
2 tbsp. butter
2 tsp. vanilla

Stir together syrup, sugar, cocoa, and boiling water. Bring all to a boil and simmer 5 minutes, stirring now and then. Add butter and vanilla. Remove from stove. Serve hot or warm over ice cream.