In a large bowl, beat the egg whites to soft peaks. Add the sugar gradually to the egg whites, beating all the while. Add in the whipped butter. The icing may clump at this point if the butter is at all chilled. Don't worry, it just means that the icing will require more beating. Beat until smooth.
3.
Melt the chocolate in a double boiler or the microwave. Cool slightly; the chocolate should still be fairly warm. Beat into the icing.
How to ice a cake video
Watch our How to ice a cake video and see how to ice cakes with ease. You'll be icing perfect birthday and special occasion cakes in no time!
Wow, I've just made this for my daughters birthday cake and it's so light but really indulgent. I was a bit worried as it seemed quite tricky but its actually not too hard.