I've been making "homemade" hot chocolate for years now. It's real simple, just a few ingredients;
1-2 tsp sugar
1-2 tsp powdered milk(preferred) or Coffee Creamer
1/2 tsp powdered baking Cocoa
In one cup mix the above ingredients, in another microwave a cup of boiling water and add to the mixture. Add marshmallows and enjoy!
I got this idea years ago from Miserly Moms or Tightwad Gazette, don't recall which. We haven't bought hot cocoa mix for years. For Christmas this year, a good friend got us some European hot cocoa mix that the kids couldn't wait to try. Their response? "Could you make yours please mom?" I don't know if they're just used to mine or if it's really that much better, but it sure is cheaper! With this cold weather, it makes an easy, inexpensive treat!