Place the milk in a thick bottomed saucepan. Heat the mixture on medium-low flame until the milk begins to steam with constant stirring. Reduce the flame to a gentle simmer.
Add the chocolate and 1 teaspoon of cinnamon to the hot milk and whisk constantly by hand until the chocolate is completely melted. Remove from the milk from the stove and mix in the whisky.
Pour the hot chocolate into serving mugs and top them off with a few marshmallows and dust with the extra ground cinnamon. Serve with the hot chocolate with the peppermint sticks and extra marshmallows on the side.