2 oz aged Venezuelan rum5 oz hot water2 oz butter base
instructions :

Whisk all of the ingredients together thoroughly. Grate nutmeg on top.

Butter base:

Combine 1 stick butter with ¼ cup of demerara sugar and ¼ piece nutmeg, grated. Let the butter come to room temperature and stir in the sugar and nutmeg until well-mixed. Roll into plastic wrap and store in fridge.

source :
imbibemagazine.com