Preheat oven to 350° F (180° C). Spray 9 inch springform pan with nonstick cooking spray, cover outside bottom of pan with aluminum foil and place in a rimmed baking sheet. Set aside.

In a microwave safe bowl, combine chopped chocolate and butter. Heat for 30 seconds, stir and heat for an additional 15-20 seconds and stir.

Continue to heat at 15 second intervals and stir after each interval until smooth. This usually takes a minute to a minute and 20 seconds. Set aside and allow to cool.

In a large bowl, combine sugar, eggs, cocoa powder, vanilla, and salt. Mix until smooth.

Add melted chocolate to sugar mixture and mix until well combined.

Poor batter in prepared pan. Set aside.

In a microwave safe bowl, heat chopped chocolate for 30 seconds and stir. Heat another 15 seconds and stir. If chocolate is not smooth, continue to heat and stir in 15 second intervals. Set aside and cool.

Beat cream cheese and granulated sugar until well combined.

Slowly add cocoa powder and mix until well combined.

Add eggs one at a time and mix. Add sour cream and vanilla and mix until combined.

Fold in melted chocolate until well combined.

Pour cheesecake batter on top of the cake batter and evenly spread cheesecake batter.

Place cheesecake on rimmed baking sheet in oven and pour about 4 cups water into baking sheet.

Water bath is optional but it helps prevent cracking.

Bake for 50-60 minutes.

The cake is done when the sides of the cheesecake are stiff and the center has a slight wiggle.

The internal temperature should be between 150°-155°.

Let cool completely.

Place metal bowl and whisk attachment in freezer for 10 minutes.

In a small bowl, add chocolate chips. Set aside.

Heat ¼ cup heavy whipping cream for 30 seconds in microwave. Pour hot cream over chocolate chips. Stir until smooth. Set aside and cool.

Sprinkle gelatin over cold water in small bowl. Let sit for 1 minute. Add boiling water and stir until gelatin is completely dissolved. Cool slightly.

In chilled metal bowl, beat remaining 1 cup heavy whipping cream until stiff peaks form. Add powdered sugar and vanilla; mix until combined. Pour in gelatin mixture and beat until well blended.

Fold in chocolate ganache until well blended.

Spread over cooled cheesecake and refrigerate for two hours. If cheesecake is not cooled, refrigerate until cake has cooled.

Heat heavy whipping cream for 30 seconds in microwave. Pour over chocolate chips in a small bowl. Mix until well combined.

Once cooled, spread on top of mousse layer.

Refrigerate cheesecake for at least 4 hours or overnight.