Preheat the oven to 350F and grease and sugar a 8" springform pan.

In a heavy saucepan, add the halved and scraped vanilla bean, water, and sugar. Heat over medium heat until it comes to a boil.  Remove from heat and set aside for at least 10 minutes to cool.

In a double boiler oven medium low heat, add the dark chocolate and gently melt. Once half way melted, carefully add half of the syrup and whisk in with the chocolate.  Once incorporated, add the rest of the syrup and whisk until thick and viscous.

Add the eggs and yolk once at a time.  Add the salt and mix to combine.  Add the room temperature butter 1 tbsp at a time and whisk to incorporate.  The mixture should be thick.  Pour the mixture into the prepared springform pan and bake for 50-60 minutes until completely set in the center.  Let it cool for 1 hour in the pan before unmolding. Serve with freshly whipped cream.