Preheat the oven to 350 degrees F.
Place the cream cheese, sugar, cocoa, and salt in a large mixing bowl and mix on medium-low speed until smooth.
Add the eggs, one at a time, scraping the bottom and sides of the bowl with a silicone spatula after each addition.
Scrape the bottom and sides of the bowl with a silicone spatula, and stir in the yolks, cream, melted chocolate, and vanilla.
Pour the batter over the prepared crust, place the cake pan in a larger baking dish, and pour water into the larger dish until it comes halfway up the sides of the pan.
Bake the chocolate cheesecake for 20 minutes at 350 degrees F, then lower the oven temperature to 250 degrees F and bake for another 60 to 65 minutes, or until set around the edges but still slightly wobbly towards the center.
Turn off the oven and prop the door open with a wooden spoon. Allow the cheesecake to cool slowly in the oven for at least an hour.
Allow the cheesecake to come to room temperature, then chill it in the refrigerator for at least 2 hours (or preferably overnight).