01 -
Combine whole milk, heavy cream, and vanilla extract in a medium saucepan. Warm over medium heat, stirring occasionally, until steaming but not boiling.
02 -
Remove saucepan from heat. Add chopped bittersweet chocolate and whisk until melted and fully smooth. If needed, return saucepan to low heat briefly to ensure the chocolate is completely melted.
03 -
Pour hot chocolate into demitasse or espresso cups. Serve immediately, optionally topped with whipped cream, and provide sparkling water on the side if desired.