If you are worried, what I do is half way through when I notice the outsides are cooking and the middle isn't, I then cover it with foil. A trick I learnt from a home economist
i couldn't tell is wasn't cooking the middle until i put a skewer in as the outside looks cooked.

Cake has been in 1hr now and cooking still but is still not totally cooked in middle ... will give it another 5-10mins then pull it out as reckon it will end up being unedible

... Rouge i most likely be making another cake tonight (can't see this one working out) so will pop the foil on half way through !!! (thanks for that Rouge).