In a small pot, heat whole milk, cream, and brown sugar over medium heat.
Use a digital scale to weigh out 7 1/2 ounces of chocolate; add 2 servings of your P+P Baking Bar (1/2 ounce total).
Bring cream + milk mixture to a simmer. Remove from heat; add vanilla and ground cinnamon, and pour over chocolate. Allow cream to melt the chocolate for a few minutes before combining with a whisk.
Whisk until mixture is homogeneous and smooth.
Portion your “chocolat chaud” into 2 large mugs, and top with fresh whipped cream or marshmallows.