In a saucepan over medium heat, add cream, milk, salt, powdered sugar, and chocolate chips. Heat over medium heat, stirring and scraping chips from bottom of pan, until hot but not boiling and chocolate chips have fully melted.
Remove from heat and stir in liqueur and vanilla. Pour into small glasses or mugs. Top each with whipped cream and a white chocolate truffle. Lightly dust tops with cocoa powder and cinnamon.
Liqueur can be omitted for non-alcoholic.
Less cream and more milk can be used for a less decadent hot chocolate.