Set your bowl aside to chill well before you begin, giving it 15 to 30 minutes so it is properly cold.

When ready, pour in the heavy cream, sugar, and vanilla. Whip until the cream thickens and holds firm peaks. This can be done by hand or with a mixer, just be careful not to overwork it. Once it is smooth and stable, set it aside until needed.

Prepare a gentle bain-marie by bringing water in a saucepan to a soft simmer. Use a bowl that sits over the pot without touching the water. Place the bowl on top.

Add the egg yolks and sugar into the bowl and whisk steadily until the mixture becomes slightly thick and creamy, like a light custard. Add the chopped chocolate and cream, then place it back over low heat. Stir gently until the chocolate melts and the mixture turns smooth and glossy.

Remove from the heat and stir in the vanilla, coffee, and a pinch of salt. Mix well, then let it rest briefly for about five minutes so it cools slightly but stays soft.

Set aside about half a cup of the whipped cream for serving. Gently fold the remaining whipped cream into the chocolate mixture using a spatula.

Work slowly, lifting and folding until the color is even and no streaks remain. Keep the motion light so the mixture stays airy.

Spoon the mousse into serving cups and let it rest until set, about three hours or longer if needed.

Finish each serving with the reserved whipped cream, and if you like, add a few chocolate shavings and coffee beans on top.