In a medium saucepan, mix SCHARFFEN BERGER Unsweetened 100% cacao dark chocolate cocoa powder and sugar with a few tablespoons of milk to make a paste.
Stir in the rest of the milk and vanilla extract, and whisk to combine.
Cook over low heat, stirring continuously, until hot. Do not allow to boil.
Serve hot, topped with marshmallows or whipped cream.