Hi Help please. I have been asked to make a christening cake fully decorated with fondant icing, decorations etc. The only problem is that they want a chocolate sponge and I'm worried it won't be dense enough to take the icing etc. Any suggestions please?
Most chocllate cakes should be able to take the weight of a thin layer of rolled fondant icing but you should avoid the very delicate whisked sponges (the type made by whisking eggs and sugar rather than creaming butter and sugar). Nigella's Buttermilk Birthday Cake (from Domestic Goddess) is a good cake for this type of decoration and can hold the weight of fondant. You could try substituting some of the flour with unsweetened cocoa powder to make a chocolate version (though we have not tried this ourselves so can't give quantities).
We would also suggest trying Nigella's Devil's Food Cake from Kitchen. This cake has a great texture - a close crumb without being dense - and would likely hold up well under rolled fondant icing. You would probably need to make a buttercream instead of the fudge icing, to fill the cake with and also to put in a thin layer over the cake before adding the fondant icing.