In a medium bowl, stir together the chopped chocolate, instant coffee, and salt.

Heat the cream, sugar, and vanilla in a saucepan over medium heat, stirring constantly until it starts to simmer.

Pour the hot cream mixture over the chocolate mixture and let it sit for 1 minute.

Whisk the chocolate and cream mixture for 1 to 2 minutes until well combined.

Pour the mixture into four small espresso cups, tapping to remove any air bubbles.

Chill the pots de crème thoroughly in the refrigerator for at least 4 hours.

Serve the dessert topped with grated chocolate or add a dollop of lightly whipped cream and dust with cocoa powder.