Welcome to the Cake Decorators Q&A

I’ve been asked to make a double decker bus, and I’m quite new to cake decorating. I thought I’d try Mrs Jones Vanilla sponge recipe and ganache, then freeze until I need it.
I thought I would do a 10″ square cake, cut in half and stacked on top of each other. That would mean cooking in one 10″ square tin. Can anyone advise on both the quantities I should use, and how long I should bake for? Many thanks.
Jacqui

Hello Jacqui

To scale up Mrs Jones’ recipe you’ll find my ready reckoner or the cakeometre tools here:
http://www.cakeflix.com/blog/how-to-work-out-what-size-cake-tin-to-use
For the ganache quantites take a peek at my chart here:
http://www.cakeflix.com/blog/how-to-ganache-cakes-without-gnashing-your-teeth

I can’t tell you exactly how long to bake your 10″ square because all ovens bake differently. In my oven I would probably bake it for between an hour and a half to one and three quarter hours. I would reduce the temperature down to 150c fan because there is at least 22% more mixture in a deep square cake which will take a lot longer to bake in the centre. This is just a guide, you will need to babysit your cake and note down the done time for future baking. Check the cake after an hour and half by inserting a wooden skewer in the centre of the cake. If the cake is done the skewer will come out clean or with just a couple of little crumbs. If it’s not done the skewer will come out with wet batter clinging to it. In this case bake on, checking every five minutes until the skewer comes out clean. If the cake is still wobbly after one hour thirty minutes bake it for another fifteen minutes and check after that time to check for doneness. You may need to bake on, check as before.
My blog on baking times and solutions might help with understanding why it’s difficult to give precise timing. See the blog here:
http://www.cakeflix.com/blog/baking-problems-solutions
An alternative to baking a deep sponge cake would be to make a large sheet cake which can be cut up and stacked for the bus shape. Sheet cakes are shallow and rectangular. The batter spreads out across the whole pan reducing the bake time and the risk of the sponge collapsing. Here is an eg and recipe for sheet cake: http://www.cakeflix.com/questions/victoria-sponge-cake

Extra precautions to take when baking large deep square cakes:
Double line the tin and protect the corners with extra lining to prevent them burning and becoming dry. I use three Ateco heating cores in larger square cakes. These help to spread the heat in the batter and allow the cake to bake more evenly. Here are the heating cores:
http://www.thecakedecoratingcompany.co.uk/heating-cores-set-of-4-by-ateco
If you haven’t got the ateco cores, metal royal icing nails will do the same. Wrapping the outside of the cake tin with bake even cake strips will also help, to see the product google ‘wilton bake even cake strips’ or you can make your own by wrapping wet towelling in several layers of baking foil. Wrap the strip around the tin securing with a pin. If you search in youtube
‘how to make cake baking strips’ you’ll see step by step tutorials on how to make them.

Hope this helps.

Thank you MIWL