What went wrong with my pain au Chocolat?

[winnie]

I tried sooo many times making these pain au Chocolat, but everytime they ended up very hollow in the middle with a thick crust. Anyone know what went wrong? Weird thing is, I use the same recipe for my croissants and they turn out fine with a nice honeycomb inside. It's always just these pain au chocolat that fail!!

I put them shaped overnight in the fridge, and then proofed them the next day for two and a half hours at 28 degree Celsius.

 

[winnie]

 

[retired baker]

I'd say, at a guess....

first I suspect you used dry yeast. No good.

Second they're underproofed.

3rd, retarding the rolled croiss overnite pretty much ruins them. The dough absorbs moisture and layers stick to each other.

4th Proofed too cool, increase temp to 33C and add GOBS of steam so the heat can penetrate.
They will proof in 50 minutes instead of hours.