For topping: Whipped cream, - marshmallows, caramel, or hot fudge
In a small saucepan, heat the milk over medium high heat until steaming and small bubbles form around the edge (do not let the milk boil!). Add the chocolate chips and let melt, stirring occasionally, then whisk until smooth.
Whisk in any desired mix-ins. Serve hot with desired toppings.