I made this cake twice recently. With the same result: it collapsed on the counter, when it was cooling off, reversed on a bottle.
I have been checking my oven temperature and it seems o.k., but, after 30 minutes, the cake tester was wet. I left it 5 or 10 minutes more, checking regularly. When I removed it from the oven, it has begun to shrink from the sides, so, it was no surprise that it felt on the counter.
The pan is the right size, I think (the batter almost fills the pan: there is approximatly 1 inch left).
Is it possible that the cake tester should be not perfectly clean when the cake is ready?