Cheesecake Layer
Preheat the oven to 300ºF and grease an 8-inch round baking pan with a removable bottom. Line the pan with parchment paper and grease the paper.
In a large bowl, beat the cream cheese on medium for 1 to 2 minutes, until super creamy. Beat in the sour cream, then beat in the sweetener and vanilla extract until well combined.
Beat in the eggs one at a time until just barely incorporated, scraping the beaters, and the bottom and sides of the bowl in between.
Pour the filling into the pan and gently shake from side to side to even it out. Tap lightly on the counter to release any air bubbles. Bake 30 to 40 minutes, or until the edges are set and the center still jiggles slightly. Remove from oven and let cool completely.
Run a sharp knife around the insides of the pan and remove the sides. Wrap tightly and place in the freezer until solid.

Chocolate Cake Layers
Preheat the oven to 350ºF and grease two 8-inch round cake pans very well. Line the bottoms with parchment paper and grease the paper.
In a large bowl, whisk together the coconut flour, sweetener, cocoa powder, protein powder, baking powder, and salt. Stir in the eggs, oil, and vanilla extract until well combined.
Stir in the coffee about ¼ cup at a time until the batter is thick but easily scoopable. Divide the batter evenly between the two pans and spread to the edges.
Bake 15 to 20 minutes, until the tops of the cakes are just firm to the touch. Remove and let cool before loosening the edges and flipping out onto a wire rack.

Chocolate Frosting
In a microwave-safe bowl, place the chopped chocolate. Melt in 30 second increments, stirring in between until smooth. Alternatively, you can melt the chocolate in a heat-proof bowl set over a pan of barely simmering water. Set aside to cool to lukewarm.
In a large bowl, beat together the cream cheese and butter until very smooth. Beat in the sweetener and vanilla extract, then add the chocolate mixture and beat until smooth. Add two tablespoons of the heavy cream and beat until well combined.
In another bowl, beat the remaining heavy cream until it holds stiff peaks. Carefully fold the whipped cream into the chocolate frosting until no streaks remain.

To Assemble
Place one layer of chocolate cake on a platter or cake stand. Use about 1/3 cup of the frosting to spread the top of the layer, all the way to the edges.
Remove the cheesecake layer from the freezer and carefully flip onto the cake. Remove the parchment paper if it has stuck to the bottom. Spread the cheesecake layer with another 1/3 cup of the frosting.
Place the second layer of chocolate cake on top of the cheesecake. Spread the top and sides of the cake with more frosting. Place any remaining frosting in a piping bag fitted with a star tip and pipe rosettes around the top edge of the cake.