Place the chopped dark chocolate in the blender and set aside.
In a medium saucepan, combine heavy cream, whole milk, egg yolks, malted milk powder, and both portions of granulated sugar; whisk to combine.
Heat the mixture over medium, whisking constantly, until it is just below boiling and thickens enough to coat the back of a spoon (do not boil).
Carefully pour the hot milk mixture over the chocolate in the blender, cover the lid with a kitchen towel to prevent splatter, and blend until completely smooth.
Strain the blended custard through a fine mesh strainer into a pouring container to remove any solids, then divide the mixture among ramekins or small jars.
Chill the pots de crème in the refrigerator until set, about 2 hours.
Before serving, top each pot with sweetened whipped cream and crushed malted milk balls.