In a large saucepan, combine cocoa powder, sugar, and salt. Gradually stir in the water and simmer over low heat 6 to 8 minutes, stirring occasionally. Gradually add half-and-half and vanilla and heat, but do not allow the mixture to boil.
Meanwhile, assemble marshmallow snowmen by inserting 2 pretzel sticks in one marshmallow for the arms. Then for the head, attach the cinnamon red hot candies to another marshmallow with a bit of the decorating icing, for nose. Use the black decorating icing to create the eyes, mouth and face and buttons. (See photo.)
Remove hot chocolate from heat and pour in mugs. Float the head up against the edge of the mug and place the “body” of it below the head as shown. Enjoy …before the marshmallows melt.