The Chocolate Guinness Cake is always very popular, no matter who I bake it for. I've been asked to bake it for my brother's wedding and I plan to do 3 tiers with 3 layers on each tier, finishing it with semi-naked frosting. I don't think the normal whipped cream cheese icing will work for this - are there any recommendations for a firmer icing that would taste equally delicious with the cake?
Nigella's Chocolate Guinness Cake (from FEAST) is a popular cake and is topped with a frosting that is a mixture of cream cheese and whipped cream. The frosting resembles the frothy topping on a glass of Guinness but is quite soft and probably not so suitable for sandwiching a cake together. A semi-naked cake is one that has a very thin layer of frosting on the sides, so that some of the edges of the cake layers show through. They are often decorated with fresh flowers or fruits.
You need a firmer frosting for this type of cake decoration and a cream cheese frosting that has a high proportion of butter may be suitable. Nigella's Red Velvet Cupcakes are topped with a frosting that is half butter and half cream cheese. To help to stabilize the frosting we suggest beating the butter and icing sugar (confectioner's sugar) together first and then beating in 1 teaspoon of cornflour (cornstarch) for each 100g (4 ounces) cream cheese. Finally beat in the cream cheese gradually, followed by any flavourings. You may like to consider draining the cream cheese overnight (in the fridge) in a strainer lined with muslin or cheesecloth, to remove as much moisture as possible. The iced cake should be kept in a cool place so that the frosting becomes firm. Otherwise a vanilla Italian meringue buttercream would be an option as this icing has a light texture but will set fairly firmly in a cool place. For special events it is always a good idea to make one tier of the cake, plus frosting, as a trial run. Also bear in mind that a tiered Chocolate Guinness Cake with 3 layers in each tier will be quite heavy, so you need to make sure that you have sufficient support for the layers by dowelling the lower layers and putting a thin cake board underneath each layer. It may also be wise to plan to stack the cake on-site at the reception.