Quick question about the 10 incher I'm making!

[BedHog]

I've made a 10 inch circular chocolate victoria sandwich using half a pound each of butter, sugar and flour/cocoa mix, with 4 eggs. I just need to cook the thing and I'm not sure how long for. I doubled the quantities from a 7" recipe which said 180 degrees C for 25-30 minutes. Presumably I have to increase the time as it's bigger, but how long should I cook it for? (roughly, obv I'll look at it first to make sure it's risen etc)

Thankyou!

Anyone? I've put it in the oven now so if nobody answers it will either be burnt or raw!!!

It's been in 20 minutes now...

it'll probably take 35 to 50 mins depending on your oven

Thankyou!!

It's starting to rise now. Do I just stick a knife in the middle to see if it's cooked or is there a better way?

Presumably you've took the cake out by now, but for future reference, use a chopstick or something else long and thin to poke in the middle. If it comes out wet then it isn't cooked!

Thanks yearning - yes it's out now! I left it in for 40 minutes but it didn't rise a huge amount so I think it's going to be a single layer cake! Just need to ice it now.