I asked my Spanish teacher about the mystery churros and she'd never heard of such a thing. So I had a good reason to be surprised. I finally hit on a useful search term for them- hand-stretched churros. Here's a very short video. And another. I didn't totally make this up even though this video is from Arizona. I'll have to come up with a recipe and post it here.
There's an ice cream place near Parque Metropolitano called Gary Choc. That's pretty much the worst name ever, but they have really good mint chocolate chip ice cream. It's on Sebastian Bach and it's in someone's house but they have a good sign up. I still like Chapalita better, but they don't have mint chocolate chip.