Covering a sponge cake with fondant need not be a stressful job, with a little bit of practice, you’ll be amazed at how good you get with it! All you need to cover a cake with fondant is to apply a thin layer of buttercream or jam that acts as a glue and also smooths out the cake.
A fruit cake is usually coated with apricot jam before being covered by marzipan, then a layer of fondant. As I don’t like marzipan, I usually just cover it with a layer of fondant over the jam.
Using rolled fondant/sugarpaste – see the fondant page for homemade recipe and more do’s and don’ts.
Always knead it, adding a little white vegetable fat, for a couple of minutes before each use to warm it and make it pliable. This will get rid of any “tightness” and ensure that your icing doesn’t crack as you lift it and cover the cake. The adding of the fat is, in my opinion, essential if you want to prevent cracks.
If you’re not sure on thickness, use spacers, 4 or 5 mm (about 1 eighth of an inch) is perfect. I know we all like less fondant on our cakes but a too thin fondant has a greater tendency to stretch as you lift and drape, resulting in tearing. Use a smoother and your hands to smooth out the paste but make sure that your hands are clean and dry to prevent marks on the paste. To fit the fondant, lift and place over the cake, not stretch which will result in tearing.
How much fondant do I need to cover a cake?
Round (about 3 in/7.5 cm high)
6″ – 4oo g (14 oz)
8″ – 500 g (18 oz)
10″ – 700 g (24 oz)
12″ – 1 kg (36 oz)
Square (about 3 in/7.5 cm high)
6″ – 600 g (22 oz)
8″ – 850 g (30 oz)
10″ – 1 kg (36 oz)
12″ – 1.4 kg (50 oz)
1 portion of buttercream is enough for 2 coats on an 8″ cake and some left over for piping top and bottom of cake. This is approximate as a lot depends on the consistency of the buttercream.
When you’ve covered your cake, you’ll be ready to decorate it or stack it, if you are doing a multi-tiered cake. Check out the Cake Decorating Page for how to stack and dowel cakes. And for some decorating ideas: