scaling up cake recipe - 9" square cake - UPDATE with pictures

Hi, Jill! Don't know anything about fan ovens - I only use gas.

If it were my cake, I'd put some foil over it (or a thick tray on a shelf above it - my Rayburn has a shelf for just that purpose) turn the heat down a bit and let it cook longer. That way gives the inside a chance to cook. Don't think it'll be completely spoiled.

HTH, Penny. x

I hate to be the one to say it, but i don't think that you have scaled the recipe up enough. for a nine inch square tin you would need sufficient for a 10 inch round tin, and a mix based on 6oz doesn't sound enough to me. I have a feeling that when I made a 10 inch round cake i either tripled or quadrupled my usual recipe. What you really need to do is work out the volume of each tin and divide the larger one by the smaller to get number to scale up by.

I wonder if a basic sponge mix actually works for this type of thing, or whether you should perhaps have used a slightly more solid cake type. Thinking about it I didn't use a sponge recipe.

So, you need a large cake that you can carve for a novelty cake, right?
I have loads, and I mean loads, of pages ripped out of magazines over the years and quite possibly have a suitable recipe but it is bedtime now so it would have to be tomorrow.

OMG - I have just googled "Lightning McQueen" and discovered that it is a car! rather you than me.

It seems that you should use a Madeira cake recipe. This makes sense as it is a cake rather than sponge, and will "carve" more cleanly than a sponge, which I reckon would end up as a pile of crumbs once you started wielding the knife :eek:

Madeira cake keeps well wrapped in foil or in a tin for 7-8 days, or you can freeze it. Cakes can be decorated a few days before a party (the instructions for the various cakes in the article are all decorated with fondant icing if that helps at all).

Work out how much mixture is required by using a measuring jug to fill the tin with water to the level that you want the cake to rise; for every ¾ pint (450ml) you will need a 1-egg, 2oz butter, 2oz sugar, etc mixture. If the tin has a loose bottom, line it with foil, then fill up with water and calculate quantities.

For an 8” round or 7” square tin you would need a 4 egg mix, and by my rough calculations you would need a 7 egg mix for a 9”, and possibly an 8 egg mix for increased depth, but of course that would depend on how deep your tin is.

For an 8” round or 7” square

8oz butter
8oz caster sugar
4 eggs, medium
½ level teaspoon vanilla essence
8oz self-raising flour
4oz plain flour

Line and grease the tin. Cream the butter and sugar together until light and fluffy. Add the eggs, one at a time, beating well after each addition. Stir in the vanilla essence. Sift the flours together, then fold into the creamed mixture to give a soft dropping consistency. If the mixture is too stiff, fold in 1-2 tablespoons water. Spoon into the tin. Level surface, then hollow out centre to a depth of about 1”. Bake above centre of oven , Gas mark 3, 325F, 160C, for 1½ - 1¾ hours. Smaller shallower cakes will take less time and larger ones a little more. Test by inserting a fine skewer into centre of cake – it should come out clean when the cake is done.

Presumably in your fan oven position won’t really matter, and you would use 150C.

Good luck, and please let me know how it turns out. A picture would be good if you are brave enough.