Question about chiffon cake
I was just looking into trying this myself (after a disastrous attempt at bundt cake - tasted fine but broke in half coming out of the pan) anyway, I found a great site with lots of tips https://www.justonecookbook.com/how_to/perfect-chiffon-cake/ but what I also found, were other chiffon cakes where this had happened, and rather than it being a failure, people would decorate the groove with fresh fruit and icing sugar. So as long as it tastes good, just embellish it.