Preparation time: 20 minutes (a day in advance)
Cooking time: None
Cooling : 12 hours

1. Melt the chopped chocolate in a bowl set over a pan of hot water.
2. Once the chocolate is melted, remove from the heat and add the butter (in small pieces), sugar and vanilla.
3. Stir until very thick and smooth.
4. Pour the mixture into the buttered mold and refrigerate for at least 12 hours.
5. Unmold the marquise and stick the macaroons into the top.