Hotpoint fan oven cuts out...then comes back on

Hi all. Hope someone can help
My Hotpoint SH 53 XS built in fan oven ofren cuts out as it overheats then if left for a period of time switches back on again. When this happens the cooker completely shuts off including the timer/clock
My first thought is the thermostat at fault but there is also a thermal switch in there too.
Any idea on pinpointing the issue so Im not buying and changing parts uneccasarily?
Thanks for any advice
Pete

It’s probably the cooling fan for the electronics that has failed.

I should have mentioned that it only does this mid cook - does this still sound like the case?