In a heatproof bowl, combine the chopped bittersweet chocolate. In a saucepan, heat the heavy cream and whole milk over medium heat until just simmering. Pour the hot cream mixture over the chocolate and let it sit for a minute to melt the chocolate.

Mix the Egg Yolks

In a separate bowl, whisk together the granulated sugar, egg yolks, and vanilla extract until well combined.

Combine and Cook

Slowly pour the warm chocolate mixture into the egg yolk mixture while whisking continuously. Return the mixture to the saucepan and cook over low heat, stirring constantly, until the mixture thickens enough to coat the back of a spoon (about 5-7 minutes). Do not let it boil.

Add Coffee and Salt

Remove from heat and stir in the strong brewed coffee and sea salt.

Chill

Pour the mixture into individual serving cups or ramekins. Cover with plastic wrap and refrigerate for at least 4 hours or until set.

Serve

Before serving, whip some heavy cream to soft peaks and dollop on top of each pot de creme. Sprinkle with cocoa nibs and additional sea salt.