1/2 c. shortening
1/2 c. butter
1 tsp. vanilla
4 c. sifted powdered sugar
3/4 c. sifted cocoa
3-4 tbsp. milk
3 tbsp. light corn syrup

Cream shortening, butter, and vanilla together until light and fluffy. Gradually beat in sugar and cocoa on medium speed, scraping down bowl often. Add milk and corn syrup until light and fluffy.