I normally bake Victoria sponge cakes using an 8-inch tin for 50 minutes at 160c (320f), on the fan/forced air setting.
Today I attempted a 10-inch, same temperature but increasing the time to 1 hr 15 mins. However, the middle sank when I removed it from the oven, and the skewer test showed that it was uncooked in the centre.
It was already browning so didn't want to risk increasing the time any further. What else could I have done differently?
I did fill the 10-inch tin more than I would an 8-inch, so perhaps I should have stayed with the same depth?