½ cup water
¼ cup granulated sugar
2 tablespoons unsweetened cocoa powder
2 teaspoons instant coffee
2 ounces chopped bittersweet chocolate
2 cups whole milk
½ teaspoon pure vanilla extract
Whipped cream (optional; for garnish)
Unsweetened cocoa powder (optional; for serving)
1. Combine the water, sugar, cocoa powder, and coffee in a small saucepan and cook over medium-high heat, whisking constantly, until the mixture is hot and bubbling. Remove from the heat and whisk in the chopped chocolate until smooth. Return to the heat and add the milk, cooking and stirring until just heated through (do not boil). Remove from the heat and stir in the vanilla.
2. Pour the hot chocolate immediately into four teacups. You can top the hot chocolate with a dollop of whipped cream and a dusting of cocoa powder.