Indeed, the exterior look of the cake is not necessary a good proof of the doneness: your cake might have a golden crust from the outside, but might be not cooked well inside.
So here’s a good old trick
When you want to check if your cake is properly cooked, open your oven’s door then pull the cake pan and prick a knife blade vertically in the center at mid-height:
- If the blade comes off with sticky dough, then you’ll still have to wait.
- If the blade comes off dry, then the cake is cooked!
Simple isn’t it? Well, that’s the kind of old tricks that are easily overlooked but very useful.