While I consider myself somewhat of an expert in marshmallows, I admit I’m not one in hot chocolate (is anyone?) I led a Hot Chocolate Crawl recently for the NYC Chocolate Meetup, and the hot chocolates varied in taste as well as viscosity. Which is “true” hot chocolate?
“Gourmet” hot chocolate isn’t the stuff you drank from a huge mug after sledding as a child. It’s thick, intense, and meant to be sipped and savored in small quantities.
We hit four locations on this particular tour, all in the East Village/near West Village.
Jacques Torres: Jacques Torres is a local chocolatier (becoming national!) and although he is famous for his chocolate products, at his SoHo plant they also have hot fresh cookies! They have an espresso bar and hot chocolate made of his chocolate, and a spicy version made with chipotle and Ancho chiles. The “classic” hot chocolate was all right, but the “wicked” version tickled all of us. Some of us were still being “tickled” by it a half hour later! It really spiced up in the back of your mouth. I found the texture a bit fluffier than I’d like. In order to make a hot chocolate a bit “foamy” you need to either add cornstarch or corn syrup, and this version felt a little corn syrup-y. But that’s just my personal opinion. Everyone chose the wicked hot chocolate as their favorite of the evening.
GROM: Our next stop was to GROM in Greenwich Village. The manager Richard was kind enough to give us a chocolate primer about the chocolates used by GROM. He and Stephano, (one of the Italian owners of GROM), owner told us the differences between chocolates from Africa (tends to be the cheapest, but also the weakest in flavor), and that from Venezuela (more expensive but more flavorful. Richard even came prepared with a handout for us! Before we tried the GROM hot chocolate, he had us try samples of the deep chocolate Gelato and Sorbet. The sorbet is made without milk or cream. While it was certainly flavorful and deep, in my opinion I missed the creamy mouthfeel that dairy provides. (Full disclosure: I am from the dairy state, Wisconsin). 
Although it wasn’t specific to chocolate, it was interesting to find out how the gelato is made and how it is different from ice cream (volume of air used!). GROM also uses a specially-sourced Italian mineral water, and has land allocated in Italy specifically for growing the fruit used in their products.
Now to the hot chocolate. The flavor Richard gave us was the “dark hot chocolate” and it certainly was. Very flavorful, but we could only handle a few sips – it’s basically chocolate melted down. More like a chocolate sauce.
Wishcraft was third place we visited. While the thin and watery hot chocolate was certainly a nice palate break from the thickness of GROM, it was unimpressive. Some people commented that the hot chocolate tasted like it was made from a powder.
Dessert Truck was last. I am a frequent customer to the Dessert Truck late nights in the East Village (where it’s parked on 4th ave & St. Mark’s place until midnight.) The Dessert Truck hot chocolate is made from Valhrona and Guittard chocolates. But he forgot to give us the marshmallows! 
Everyone agreed that the Jacques Torres spicy hot chocolate was the favorite. It was complex and wasn’t too thick or too thin. GROM and Dessert Truck hot chocolates were tasty but we all thought the texture was more like chocolate syrup.
All in all a fun trip on a cold night!