In a small saucepan, whisk together the milk, heavy cream, egg yolks, sugar, and salt. Over medium low heat, cook this custard mixture to thicken, stirring constantly and being careful not to allow it to simmer and curdle. When it starts to steam and thicken enough to coat a spatula (around 170 degrees), remove from heat and pour over the chocolate into the blender. Blend on medium speed until chocolate is melted. Divide into 6 small glasses, ramekins, or plastic cups. Refrigerate until set, about 4 hours. Dollop with whip cream and top with a few raspberries to finish, if desired.
