1 cup whole milk
1/2 cup heavy cream
1/2 cup natural unsweetened cocoa powder
1/2 cup packed light brown sugar
3/4 tsp. pure vanilla extract
2 cups ice cubes
3 Tbs. bittersweet or semi-sweet chocolate shavings (made with a vegetable peeler)
Blend the milk, cream, cocoa, sugar, vanilla, and a pinch of salt in a blender until well combined and the sugar is dissolved. Add the ice and blend just until slushy. Transfer to glasses, top with the chocolate shavings, and serve immediately with spoons.
You can also add a 1/4 cup of coffee to give this a coffee flavor.