Upstairs of Momofuku noodle bar is the Momofuku Milk Bar. It's basically a huge fridge full of goodies you can purchase and you pay downstairs near the entrance. The soft serve are served near the entrance of downstairs.
We tried the cereal mlik soft serve and I have to say I am not a fan of the flavour. The soft serve is really small for the price you pay. I don't think it's worth it but give it a try if you're really, really, really curious of the flavour. In general we didn't enjoy the soft serve.
We also purchased the birthday cake truffles from the fridge upstairs. The truffles came in a pack of 3 and was very yummy. It would be something I would purchase again. I would return back to the fridge to try their other sweets.
Not much service given as you just walk in to the fridge upstairs and pay downstairs near the entrance. There's also no space for you to enjoy your treats except for the bench across from the fridge upstairs.