In a medium saucepan over medium-high heat, whisk together the milk, cream, and sugar and heat until bubbles start to form on the outer edge. DO NOT BOIL.
1½ cups whole milk, ½ cup heavy cream, 1 tablespoon powdered sugar
Remove from heat and add in the chopped chocolate and vanilla and let sit for 2 minutes. Then whisk until a rich chocolate color forms then let sit for about 5 minutes.