Most mixes are way too sweet and have too much stuff in them, but a good one is Baru in a fun striped cylinder. You can make your own with cocoa powder, milk and a mug. The key is to make a paste first with a ¼ c milk and the cocoa powder, then add the rest of the milk. Whisking gives you some frothiness. Top with whipped cream, marshmallows—the kids might like their hot choc garnished with a candy cane. Tip in a splash of brandy, Grande Marnier or peppermint schnapps to make an adult beverage. In the name of research I also had a beautiful hot chocolate at Cococo on 124 Street, similar to the following: