Lets start with the basic must haves; mini marshmallows, whip cream, cinnamon, cocoa, and cookies.
To add a little cheer I recommend adding a shot of liquor to the cup of hot cocoa. Different liquors will add different notes.
I have listed the liquors to make the hot cocoa pairing simple for your next cozy gathering.
Aged or dark rum: vanilla, caramel, spice, oak smooth
Bourbon: toasted oak, nutty, vanilla, buttery
Crème De Menthe or Peppermint schnapps: explains it self in the name.
Baileys: smooth milk chocolate, vanilla
Kahlua: coffee notes of vanilla and caramel
Galliano: star anise, vanilla, licorice
Crème De Cacao: rich chocolate
Cointreau or Triple sec: orange with a mild spice hint
Tia Maria: coffee, vanilla, caramel with hint of citrus