Place a rack in the middle of the oven. Preheat the oven to 400° F. Lightly butter a 8-9 inch spring-form pan and line with parchment paper going up the sides of the pan.Split the vanilla bean in half and use a sharp knife to scape out the seeds. In a mixing bowl, beat together the cream cheese, 3/4 sugar, and vanilla beans on medium speed, scraping down the sides of the bowl until very smooth and creamy, about 2 minutes. Add the eggs, 1 at a time until the eggs are fully incorporated. Scrape down the sides of the bowl, then reduce the mixer speed to medium-low. Add the cream and hazelnut liquor, beat until combined, about 30 seconds.Sift the flour and salt into the batter, then beat again to combine, about 30 seconds. Pour the batter into the prepared pan.Bake for 50-55 minutes, until deeply golden brown on top and still very jiggly in the center. Let the cake cool 5 minutes, then unmold. Let cool completely. Before serving, make the chocolate sauce. Combine chocolate and cream microwave-safe bowl and microwave, stirring every 45 seconds, until melted. Stir in the vanilla and coffee powder. Slice into wedges and serve at room temperature or chilled, drizzled with warm chocolate sauce.