1. Pour the cream into a bowl with the vanilla. Whip it into a chantilly and refrigerate for 30 minutes.

2. Transfer the cream into a piping bag with a star tip.

3. Pipe regular waves onto one of the boudoirs.

4. Stack another boudoir on top, pressing gently to hold it in place.

5. For the all-chocolate version, dip every other boudoir into the melted dark chocolate, and for the striped version, use a fork to drizzle the melted chocolate over the biscuit.

6. Repeat with the remaining boudoir biscuits and decorate as desired.

7. Refrigerate for 20 minutes before serving.