What's the most difficult thing you've baked?

Baklava with homemade dough so thin you can see through it when held up. I have my Grandmother's long wood rolling dowel and it was so hard to roll out dough that thin, it took me a long time to master it.

My first time making flan was my most difficult  thing  I ever baked ,but now after years of making them for holidays I finally got the right way down packed   

I can't make Banana Bread for the life of me.

I can't make that stuff.

I would test recipes and never got that down.

For some damn reason, I can't make a good loaf.

"My Father is a career chef and keeps telling me to listen to him".

Choux pastry,  its quite tricky if you haven't got the knack.

While not difficult I do make a German Chocolate Souffle Cake that requires one part of it to be made far enough in advance that it cools completely.  I make this the day before. And after that there are multiple steps before the batter is combined and baked. And as written there are 3 sauces that go with  it (I have eliminated 2)

I find few things "difficult" it is just paying attention to what I am doing.  Sometimes I am my own enemy when it comes to something "failing" it is usually because I did not read an instruction properly or tried to rush.

lobster pot pie!!

A complicated braided pastry thing. It tasted great, but it looked like a train wreck.

I once made a chocolate pecan caramel tart all from scratch and swore I'd never do it again even if the Queen came to dinner. 

Souffle, usually it drops. Or a good risotto that is somehow done perfectly long before the rest of dinner is ready and is gloppy by the time dinner goes on the table. .

Choux pastry .. for Eclairs or Profiterols.

Everything has to be 'just right' or they won't rise and/or they will collapse afterwards.