Whip the 1/4 cup of the cream and set asie for later use.
Combine chocolate pieces, sherry, salt and cinnamon in the top of a double saucepan, and cook gently over hot water, stirring occasionally, until the chocolate is melted and all the mix is well blended.
Combine the milk and half a cup of the cream in a saucepan and heat through but DO NOT allow to boil. Add to the chocolate mix, beating well, whilst adding chocolate mix.
Pour the hot chocolate mix into cups, top with the whipped cream and dust lightly with cinnamon.