A: What’s your first reaction after learning that you’ve won this year’s young writer’s prize?

    B: I was happy just to get my book published, so winning the young writer’s prize as well is the icing on the cake.

    Note: This idiom refers to the situation where you already have it good and then get something on top of what you already have. Icing is a mixture variously of sugar, butter, flavoring, water or other liquid, egg whites, etc. for covering a cake or pastries. It’s also called “frosting.” If something is the icing on the cake, or the frosting on the cake, it makes a good situation or a good result even better. “The icing on the cake” is used more in British and Australian English and “the frosting on the cake” is used more in American English.