1/2 c. cocoa
3/4 c. sugar
2/3 c. evaporated milk
1/3 light corn syrup
1/3 c. butter
1 tsp. vanilla

Combine cocoa and sugar in saucepan. Blend in evaporated milk and corn syrup. Cook over medium heat, stirring constantly, until mixture boils. Boil and stir 1 minute. Remove from heat. Stir in butter and vanilla. Serve over vanilla ice cream.