Kate's been killing it with Carl, had him in Nieman Marcus and an airport kiosk last year, there's also Carla, who is peppermint IIRC.
Inspired by Kate, I've made a single-serving version for a few years but am leaning heavily towards not this year. It does seem like a few more people on Instagram are making them. I use a 50 mm hemisphere mold, which is on the small side, 60+ mm might be easier to handle (and fit marshmallows in). I don't use marshmallows but I'm probably weird that way. I don't like them and my balls are too small.
Pros: They're cute, fun for kids of all ages, highly giftable, and people love the idea
Cons: yes it's just 2 hemispheres filled with a dry mix and stuck together, but doing that neatly is apparently beyond me. If one leaks then suddenly there's dust all over everything. You need a good lip on both halves of the mold to get a full seal. I solved that by sealing each half via some chocolate and acetate trickery, but that's an extra step. They're fragile so not great for shipping, which I expect to do a lot of this year. Finally, I feel like they don't actually work that well. In some of the videos where they just pour hot milk over, you can see it takes a bit before it melts. I've found you need to either do it on the stove-top or stir like crazy and get it super hot or you get sludgy bits in the bottom of the cup, which bugs me. Carl/Carla is big enough that you'd have to do it stove-top but for single serving I think people want to make it in the mug.
If you can put together something that's easy to execute (and you're neater with the cocoa mix than me), people will love them and you too can be insta-famous!
edited to add - I also coated mine in white to cover my messy joins and called them snowballs, more unnecessary steps! 🤣
