In a pot over medium heat bring to boil the milk with the half and half cream, sugar, nutmeg, and vanilla extract.

Once it starts boiling turn off the heat and add the cocoa powder.

Mix until all the ingredients are well incorporated.

Set the pot aside and let it cool down.

Transfer to a jar.

Optional: Mix in the vodka.

Garnish the rim of the glasses with sugar and fill them with ice.

Carefully, pour the cocktail.