Yes, the cake has to be dense for this. I once made a recipe that was so light it just didn’t work.
There are lots of easy ‘cake-mix’ recipes out there for Pineapple Upside Down Cake; but I’ve found that it’s best from scratch - and the best are the ones done in the cast-iron pan, for the caramelization.
Speaking of brown sugar, I've got 3 or so bags, sealed up tight, haven't used any for quite awhile, or very much. I have to measure it out, pack it in, then go through it with my fingers looking for hard little lumps that won't break down when you pinch them hard, throw them in the sink. They might be ok to go ahead and use but might not in some things. Anybody else have this problem?
I was thinking sometime we need to have a problem thread, things we have trouble with. Not this week though.
Yes, I could flip it with a good grip and non skid pot holders. Away from my body in case I slip, the syrup is HOT. I'm just as happy with a glass pan. It caramelizes a little, not like an iron pan.
The idea for this cake I got from two or three different recipes and added my own twist. It's a rhubarb custard cake with a mix and added custard powder, beat the thing for 10 minutes in my stand mixer. It was gorgeous though, don't know if it would hold upsidedown.
But how about pineapple instead of rhubarb? Or peaches? Might be interesting. Top is pretty but not very special occasionish though.

Now on the newer cake mixes which went down to 16.5 oz I think, from 18.5? I figure I need to add 2 tbsp flour to make all the recipes I developed work right or older recipes. Some wouldn't matter, but some would.