In top of double boiler, combine 1 pkg. Betty Crocker dark chocolate fudge frosting mix (dry), 3 tbsp. butter or margarine and 2 tbsp. light corn syrup. Gradually stir in 1/2 cup milk.

Heat over rapidly boiling water 5 minutes, stirring occasionally. Remove from heat; stir in 2 tbsp. dark rum. Cool to room temperature. Refrigerate leftover sauce covered.

2 cups sauce