PREPARATION:

To make the melting chocolate croutons:

1. Preheat the oven to 400°F.  Stir the chocolate and butter in a heavy small saucepan over low heat until smooth. Using an electric mixer, beat the egg, egg yolk and sugar in a large bowl until pale and doubled in volume.  This will take about 3 to 5 minutes.
2. Fold in the melted chocolate mixture. Add the flour and salt and stir with a whisk until smooth. Spoon into the prepared muffin cups, dividing equally.
3. At this point, the chocolate croutons can be made 8 hours ahead and refrigerated, then baked just before serving. Bake for 5 minutes, or until slightly puffed and just set around the sides (a toothpick inserted into the center of the cakes should come out with batter attached).  Let the croutons rest for 3 to 4 minutes then unmold.

Meanwhile, to prepare the chocolate and mint soup:

1. Combine the milk, 1 1/4 cups/295 ml of cream, and the coarsely chopped mint in a medium saucepan.  Bring to a gentle simmer over medium heat. Remove from the heat then cover and let steep for 5 minutes.
2. Strain the cream mixture into a large bowl. Add the chocolate and stir with a whisk until the chocolate melts and the mixture is smooth. Pour the hot soup into 6 bowls. Place 3 warm chocolate croutons into each bowl. Reserve the remaining croutons for nibbling. Drizzle with the additional cream then garnish with the whole mint leaves and serve.