Start boiling some water for a water bath while you make the batter.
Place both chocolate bars ( I broke them into small pieces) and heat in the microwave for 20 second intervals until melted. Make sure to mix well in between.
Using a mixer, beat the cream cheese, sugar, and cocoa powder on high speed for 2 minutes. It is become smooth ( make sure to scrape the bowl)
24 oz Cream cheese, 1 cup White granulated sugar, 2/3 cup Unsweetened cocoa powder
Add in sour cream, heavy cream, vanilla, both melted chocolates. Beat on medium for 1 minute. The cream cheese should be creamy and smooth. If there are any chunks, scrape the bowl and beat again for 30 seconds until smooth. Add in eggs and mix on low until just combined.
1/2 cup Sour cream , 1/4 cup Heavy cream, 1 tsp Vanilla extract, 4 Large eggs
Take the bowl off the mixer. Use a rubber spatula to fold the batter to make sure everything is combined. Pour batter on top of the crust. Use the spatula to smooth the batter.
For the water bath use a large roasting pan. It should be about 12x16 inches. Then do 1 of the 2 methods.1. My preferred method. Use a 10 inch cake pan. Place spring form pan inside the cake pan. Then fill the roasting pan with boiling water about half way up the cake pan. This method makes sure no water gets inside the crust. 2. Wrap spring form pan twice in foil. Make sure it is tight! Place in the roasting pan and fill with hot water about half way up the spring form pan.Put the pan in the oven as soon as you put the hot water in. Bake for 70-90 minutes. The cheesecake is done baking when the edges are set and the middle has a slight jiggle. If there is a big jiggle in the middle, bake for another 10 minutes and check again. Turn off the oven and prop open the oven door.. Let the cheesecake sit in the oven for 30 minutes. This helps the cheesecake slowly cool. Then, transfer spring form pan to a cooling rack. Allow to cool completely. Then, wrap in foil and place in the fridge. It needs to chill for 6 hours or overnight before decorating.