Place the chopped chocolate in a large heatproof bowl. Set aside.

In a large bowl, using a handheld electric mixer, beat the egg yolks and granulated sugar on medium-high speed until the mixture is thick, smooth, and deeply yellow. Set aside.

In a medium saucepan over medium heat, warm two cups (454ml) of the cream just until it comes to a simmer. Remove the pan from heat and slowly whisk half of the hot cream into the egg yolk/sugar mixture, whisking constantly and adding it very gradually, to temper the mixture.

Slowly add another half cup (113ml) to the bowl and whisk well to combine. Transfer the mixture back to the saucepan and cook over medium heat, stirring constantly, until the mixture is thick enough to easily coat the back of a spoon, about 5 minutes (do not bring the mixture to a boil).

Slowly pour the warm mixture over the chopped chocolate. Stir until the chocolate is smooth and melted, then whisk in the vanilla, espresso powder, and salt. Cover with plastic wrap and refrigerate until cold, about 1 to 2 hours.

Once the chocolate mixture is chilled, beat the remaining 1 and ½ cups of the cream (340ml) until stiff peaks form.

Gently fold the whipped cream into the chocolate mixture, mixing softly but thoroughly, until evenly combined.

Spoon the mousse into dessert cups, top with whipped cream and chocolate shavings, and serve at once.

In a large bowl using a handheld electric mixer, beat the heavy cream and confectioners’ sugar together until medium-stiff peaks form.

Spoon on top of the mousse, top with chocolate shavings, and serve at once.