Nutella Mousse Layer Cake

Instructions

1. Preheat oven to 375ºF. Generously grease a 10-inch round springform pan.

2. Over medium heat, melt together the chocolate chips and the butter. Stir constantly.

3. In a large bowl, whisk together the sugar, salt, vanilla, eggs, and cocoa powder.

4. Mix the melted chocolate mixture into the sugar-eggs mixture.

5. Pour the batter into the prepared pan. Bake for 20-22 minutes. It's okay if a toothpick doesn't come out totally clean. Set aside to cool inside the springform pan (do not unlock the pan).

6. Spread 1/2 cup of Nutella evenly over the cake.

7. Use an electric mixer to beat together the cream cheese, heavy whipping cream, and sour cream until smooth. Use a spatula as needed to scrape down the sides of the bowl. Set aside.

8. Over low heat, dissolve the gelatin into the 3 tablespoons of water. Stir gently until dissolved. Add the Nutella spread and continue stirring until fully incorporated.

9. Pour the Nutella mixture into the cream cheese mixture and whisk vigorously until smooth.

10. Mix in the vanilla and Cool Whip.

11. Spread the mousse over the chocolate cake layer in the spring form pan and place in the refrigerator.

12. In a stand mixer, whisk together the butter and Nutella until smooth.

13. Mix in one cup of the powdered sugar and 2 tablespoons of the whipping cream. Whisk on high speed until smooth, scraping down the sides as needed.

14. Repeat with remaining powdered sugar and whipping cream.

15. Mix in vanilla and salt.

16. Spread about 1/2 of the buttercream over the mousse layer (this is easier to do if the mousse has had enough time in the fridge to firm up a little bit, but it's not impossible to spread even if the mousse isn't completely set up yet).

17. Put back in the refrigerator to continue chilling.

18. Over medium-low heat, stir together the 1/2 cup of chocolate chips and 1/3 cup of heavy whipping cream. Continue to stir until chocolate is melted and ganache forms.

19. Pour and spread the ganache over the buttercream layer.