Combine cocoa powder, sugar, salt and boiling water in a sauce pan. Bring mixture back up to an easy boil, stirring constantly. Simmer, while stirring, for approximately two minutes. Keep a close eye on it and make sure it's a gentle boil to avoid scorching. Stir in milk and heat until hot, but do not boil. Remove from heat and add vanilla and half and half. Stir well. Top with marshmallows, whipped cream, chocolate sauce and Crushed Peppermint Candy Canes. Serve with a candy cane for stirring.