1. Add cream, milk, sugar into a large saucepan and bring to a boil over medium heat.
2. When mixture is hot, pour over egg yolks, while whisking constantly to prevent curdling.
3. Put mixture back into saucepan on low heat, stirring constantly until mixture reaches 75°C on an instant read thermometer (or coats the back of a spoon well).
4. Take off heat, and strain into another bowl. Add dark chocolate and stir well.
5. While still warm pour into cups 3/4 of the way, and let sit in fridge for 1 hour.
6. Whisk all ingredients for the Baileys cream until the mixture reaches full peaks. When pot de cremes are completely chilled, pipe cream on top. Garnish with chocolate shavings.