1. Whip the cream until stiff peaks form, then place it in the fridge to keep cold.
2. Separate the eggs, placing the yolks in a glass or metal bowl. Scrape the vanilla pod and add the seeds to the yolks.
3. Sift the powdered sugar through a fine mesh strainer into the yolks. Mix well with the vanilla seeds.
4. Place the bowl over a pot of simmering water (double boiler setup), ensuring only the steam touches the bowl. Whisk the mixture until it reaches 80 °C (176 °F).
5. Prepare an ice bath (a bowl with cold water and ice cubes). Once the yolk mixture reaches 80 °C, place the bowl in the ice bath and whisk until the mixture cools and becomes thick, sticky, and creamy.
6. Gently fold the chilled whipped cream into the cooled yolk mixture using a silicone spatula until fully combined.
7. Pour the parfait mixture into molds and freeze for about 4 hours.
8. For the chocolate soil, preheat the oven to 160 °C (320 °F).
9. Combine sugar, flour, cocoa powder, salt, and ground coffee in a bowl.
10. Melt the butter and add it to the dry ingredients. Mix with your hands until a crumbly texture forms.
11. Spread the mixture evenly on a small baking tray and bake for about 10 minutes.
12. Remove the tray from the oven, let the mixture cool, then crumble it into pieces. Store in an airtight container.
13. To serve, unmold the parfaits, arrange them on plates, and decorate with the chocolate soil around them.
14. Optional: Garnish with mint oil, berry compote, marzipan sauce, or chocolate sauce.