Cream together margarine and shortening until well combined. Add cocoa powder and mix well.
Add the icing sugar about half a cup at a time and beat well each time adding a little splash of soy milk when all ingredients have been mixed . Beat in the essences for about 3 minutes with a hand held mixer until light and fluffy. Cover with cling film and refrigerate until needed. Pipe or spread onto cupcakes and decorate with sprinkles.