For the chocolate chips, you can use milk, dark, or semi-sweet chocolate. I made mine with Hershey's milk chocolate chips. The higher the quality of your chocolate, the better your Hot Chocolate Bombs will taste.
For the hot chocolate mix, simply use your favourite one.
The Lucky Charm marshmallows can be replaced by classic mini white marshmallows.
I used this chocolate mold in large to make the bombs because I wanted a sphere of 2.64'' diameter. With this size, the bombs fit nicely in any standard mug.