Sunk cake - help me!

[Christmaspanic24]

So I followed this recipe

www.bbcgoodfood.com/recipes/sponge-cake

But... I used a 9inch / 24cm tin instead of 2 20cm tins. I cooked at the same temp and at 30mins a skewer came out clean, but it sunk and isn't cooked in the middle. The cooked bit tastes great though!

How do I adjust the temp / time for my larger tin and making it all in one?

Seems a silly error now

I'd probably just buy two sandwich tins, they won't cost much.

Alternatively you can search for a sponge cake recipe written for the tin size that you already have and see what cooking time it states.

The internet research I've just done suggests it doesn't make any difference it's a bigger tin, it's that I've baked it in a deep tin rather than two shallow tins. All the recipes I can find state the same temp but longer. I'm just worried that the cake will burn on the outside. Can anyone experienced at baking confirm the temp and time? Thanks

If it starts to brown too much on the top then stick a bit of foil over the top

If you use one tin instead of two it’ll take longer for the middle to cook through. Sorry if that sounds patronising.
Sometimes our ovens are also not as accurate as we think.
I’ve known the reverse which is when cakes form in a ‘peak’ and that’s because the oven temperature is too high.

busybee but my question is, if I increase the time do I lower the temp slightly?

I just dont want to waste more ingredients!

I’ve never found it works very well.
I know it’s what you want to do, but it’s hard to get the middle cooked before the outside is dry.

If you can’t buy or borrow a second tin, I would bake half the mixture at a time. I’ve done this. I think the second baking rises a little less but not much.