In a small saucepan, heat heavy cream until it reaches a light simmer. Pour the hot heavy cream over the chocolate and allow to stand for 2 to 3 minutes. Stir until smooth. Pour the chocolate into a shallow dish, such as a 9-inch pie dish, and transfer to the fridge to chill for 1 hour and 30 minutes.
Meanwhile, in a food processor, add the coffee, milk powder, salt and powdered sugar. Pulse until finely ground and mixed. Transfer to a shallow bowl and set aside.
Using a #20 ice cream scoop (or a melon baller), scoop out mounds of the chocolate mixture onto a piece of parchment or wax paper (they’ll look a bit like wonky circles—don’t worry!). Transfer to the fridge to chill for an additional hour. Remove from the fridge and using your hands, roll the mounds of chocolate to form a circle (don’t worry if they’re not perfect circles) and then immediately transfer to the fridge to chill for an additional 15 minutes. Roll the chocolate balls in the coffee mixture and place in mini cupcake liners. Keep refrigerated until you’re ready to serve, at which time, allow to stand at room temperature for about 30 minutes, just to take off a bit of its chill. Garnish, if you like, with a teeny dusting of powdered sugar.