Devil's Food Cake for 60

Our answer

Unfortunately scaling cake recipes is quite tricky and not something we particularly recommend. The original recipe is for two 20cm/8-inch diameter tins and there is quite a difference between this and your 30cm/12-inch tin. If possible we would suggest trying to get hold of some 20cm diameter tins and making the cake a 3-layer version rather than a 2-layer one. The 3-layer version would serve around 18 people (slightly more if it is a party as people will tend to eat smaller slices if there has been a meal beforehand) and you could make 4 of the 3-layer cakes. This would require you to make 6 batches of the cake (as you would need 12 layers in total) but the un-iced cake layers can be wrappped and frozen for a few days if they are made in advance. You could would also need to make about 1 1/2 times the icing for each cake, giving a total of 6 times the original quantity of icing (in this quantity please give it plenty of time to cool as it will likely take quite a bit longer than the 1 hour in the recipe).

In a 30cm tin the cake layers will be very thin and would need careful watching if you do bake them. We would guess the baking time to be around 20 minutes but you would need to start checking after 15 minutes. You could stack several layers together which would require quite a bit of icing but be careful when lifting the layers - they are thin and large so will could break up more easily when they are lifted. If they do break you can put them on the cake and "glue" them together with some of the icing so it is not a complete disaster but it may be easier to get a large, tin cake board or piece of sturdy cardboard to lift the cake layers and slide them on to the icing. It is probably a good idea to ice the cake the night befor you need it, to make sure that you have enough icing and also to let the icing set a little (it doesn't set firm) so that the cake is slightly easier to transport.