So it occurred to me why not try that in the apple cake? But the apricot one is sunken in the middle, too. So I have decided the dough is not heavy enough to support the cake and it should be more like the 2nd streusel photo, skinnier on the bottom but doesn't look sunken.
The case against a tube pan of any sort for streusel is you either have to cut it in the pan or somehow find a way to turn it out without damaging the streusel if they don't have removable bottoms (I gave mine away, don't really miss it but sometimes there's a particular use for every odd pan you own).
We had a German bakery, probably several as I live in a German heritage area. The couple got old and they shut it down for sanitary reasons. I went in there only once because they delivered trays of the doughnuts every Sunday to a nearby little supermarket which is history now, too. They had these marvelous little pies with rather thick crusts made in cupcake tins with papers, then filled with apple filling, a top set on, and iced. The crust was thick and possibly lard but tasted really good. No, I can't duplicate any of that either.
Bakeries come, I get a favorite or two, then they go. Happy Joe's used to have a bakery, and they had the best apple fritters and foldovers of soft puff? brioche? pastry, filled with fruit, with three lines cut in top for vents then lightly frosted (maybe not). The cream cheese or almond paste combo ones were the best. Then they went, just like my favorite restaurants.
But their trademark (back to the German bakery) which has never been replaced were berliners and large vanilla cake doughnuts with chocolate frosting; my friend thought they were potato doughnuts. I don't try to make them. There are other doughnuts from the past and present I like the best, but nothing equal to that German bakery. The current ones are chocolate chip glazed with an almost transparent glaze which gets a little hard but the doughnut stays moist (locally owned, not Krispy Kreme) Berliners are those raised deep-fried puffs, filled with a certain kind of raspberry filling and rolled in sugar.
I have saved up some recipes which looked especially delicious that are German, one is an apricot kuchen, a sweet pastry, fresh apricots sweetened I assume on the bottom, covered with sour cream and sugar and baked. The other is a plum cake made with yeast dough only richer yellow and sweet. It's an upsidedown cake with those red plums in the top. I'll see if I can find the picture for that. It's a little more ambitious than I've been able to muster so far, and I never cooked with plums before. They are not even a favorite for eating but I do if they are ripe and sweet. I like canned plums and was going to get some, haven't had any for years.
It's flickr so it's bigger than at the recipe site. Well, I had to use the flickr one as it is the only one, there are other views there of the whole cake, etc. What a hassle it is to embed photos from there, way more code than I need plus it's somebody else's account this time.
http://centerstagewellness.com/plum-cake/>
Inverted plum kuchen. Also I've got several peach/custard recipes.
But the creme de la creme is serbian from youtube. It is way too much work to make but I figured out how to do it. Basically it is a regular puff pastry dough, baked in two pieces cut to make a bottom and top of the pan to hold the dessert. It's filled with a thick layer of lots of egg yolks pastry cream blended with the whites and whipping cream. It's called Krempita.
I'm posting a photo of a similar version, also called vanilla slice. It's a favorite in Serbia and nearby places.
I was going to embed a photo of one but can't find the right one. I've done enough damage for now ;-). There's a certain Krempita one on youtube. I converted the whole darn thing from Serbian (somebody said it was a slightly different language) and metric but never made it yet.
https://www.youtube.com/watch?v=ZFXgPswkyB8 - this is the right one Krempita recept - Vanilla slice recipe
Some English/Australian recipes call for custard powder custard which is not fit to eat (they like the stuff). And forget cookie crumbs, puff pastry or I don't want it. I do use Bird's custard powder for baking cakes sometimes, adds special texture and taste or something.
Sorry, when I look through my saved recipes I come across some really delightful ones I've not been able to make. Some are disappointments, but now and then I get a real winner.