Preheat oven to 350 degrees. Line 8" round pan with parchment paper, and butter/flour sides. I use Baking Pam for this.

In heat proof bowl, pour coffee over cocoa and chopped chocolate. Let sit for 2-3 minutes, then whisk together. Set aside.

Pour into prepared baking pan.

Bake for 16-18 minutes, or until toothpick in center comes out with just a few crumbs. Let cook in pan for 5 minutes, then remove to rack to finish cooling.

Using a mixer, beat cream cheese, Nutella, powdered sugar, vanilla and salt on medium-high for about 5 minutes, or until mixture is light and smooth.

Set bowl aside. In another bowl, using whisk attachment, beat heavy cream until peaks just begin to form, about 4 minutes. Fold cream into Nutella mixture until well incorporated.

Next, put plastic over inside and sides of baking pan that you used for the cake. Then, fold a large piece of wax paper into thirds so that you have a long, thick piece. Place wax paper into pan so that it makes a tall side all around the pan.

Put the cake into the bottom of the pan. Spread Nutella mousse evenly over the cake. Put pan in freezer for at least 2 hours.

In large bowl or stand mixer with whisk attachment, beat eggs for about 4 minutes, or until light colored and thickened. Then, beat in sugar.

Heat 1 cup of heavy cream in a medium sized sauce pot over medium heat. Once cream is hot, slowly pour a little over half of the cream into the egg yolk mixture, stirring continuously (it is important to do it slowly, and stir, so that you do not cook the eggs). Then, pour the mixture back into the remaining heavy cream in the pot, still stirring continuously.

Turn heat under pot to low, and stir continuously until mixture begins to thicken, about 5 minutes. After mixture has thickened, remove from heat and whisk in chocolate chips and Nutella until smooth.

Place the egg mixture in a bowl in the refrigerator for at least two hours.

After mixture has chilled, beat remaining 1 cup of whipping cream with whisk attachment until stiff peaks form, about 5 minutes.

Fold whipped cream into chocolate/egg mixture until well combined.

Remove cake with Nutella cream cheese mousse from freezer. Spread Nutella chocolate mousse evenly over Nutella mousse and return to freezer for at least 2 hours.

After chocolate mouse is firm in freezer, make ganache. To do this, place chocolate in a heat proof bowl. In another heat safe bowl, heat heavy cream until boiling (I use a glass measuring cup in the microwave for about 30 seconds). Pour cream over chocolate and cover bowl with plastic wrap. Let sit for 5 minutes, then whisk until smooth.

Once smooth, spread ganache over top of cake, letting it run down the sides.