Nutella Puff Pastry

You know how all those food blogs have beautifully styled food, pristine dishware, amazing lighting? I would love to have one of those. Instead, I'm Lakshmi and I do things like this.
My friends and I had a potluck not so long ago, and I decided to make these Nutella puff pastries I found on Pinterest. Nutella + marshmallow + puff pastry. How could that not be a hit? They're supposed to look like this:

 

That would've been really impressive, right?

Here's how mine turned out...

FAIL! They're like little volcanoes! I should enter them into a science fair!

I made two big mistakes. I wanted to make sure there was a lot of delicious filling, so I stuffed in as much as I could, but when I folded the pastry over, it seemed to stretch it out too thin. I'm guessing the marshmallow melted right through and evaporated. Also, I used my friends' oven because I wanted them to be fresh and warm, but they said their oven gets really hot, really fast. Pshh...can't be that bad, I figured. Ugh.
People still ate them and said they were fine and I appreciated their lies, but I was SO disappointed.  I will try to make them again. I WILL conquer this!

Update (May): Tried again. Slightly undercooked and doughy, but way better than last time!

Update (Sept): PERFECTION!