Line 2 9” cake pans with plastic wrap and set aside. Note the mousse is going to be divided into two and poured into the pans so make sure the plastic is large enough to cover the full base and up the edges.

Add the chopped dark chocolate, butter, and Kahlua into a bowl. In a double boiler over medium heat, melt together the mixture. (This can also be done in a microwave in 30-second intervals). Mix in the salt and vanilla and set aside to cool slightly.

In a stand mixer or with a hand mixer, add the egg whites and whisk together on medium speed until just foamy. After the egg whites are foamy, add in the sugar and whip until medium peaks form.

Add the gelatin to the water. Mix to combine and set aside to bloom for at least 5 minutes.

While the gelatin is blooming, whip the egg yolks in a bowl with a hand mixer or the base of a stand mixer until they are pale in color. Fold the whipped egg yolks into the chocolate mixture.

After the yolks are added, heat ½ cup of heavy cream in the microwave until warm but not boiling. Add the gelatin-water mixture to the warmed cream and mix to combine. Fold the mixture into the chocolate mixture.

After the gelatin is added, fold the whipped egg whites into the chocolate mixture

Lastly, whip the remaining 1 cup of heavy whipping cream until soft peaks form. Fold the whipped cream into the chocolate mixture until combined.

Pour the mousse in the two prepared plastic lined cake pans, pouring half in each. Spread into an even layer so the top is flat. Set for at least 4 hours in the fridge or overnight

When it has been at least 4 hours and it is time to bake the cake layers, remove from the cake pans (we like to lift it with the plastic wrap and place it plastic side down on a plate) and place the mousse layers back in the fridge until assembly time

Combine the sugar, flour, cocoa powder, baking soda, baking powder, and salt into a bowl. Stir together with a whisk until evenly combined

Add the vanilla, eggs, buttermilk, and oil and stir until combined

Once combined, add the hot coffee. Stir quickly to ensure the hot coffee is evenly distributed. The batter will be very thin

Pour the batter into 3 greased and floured 9" round cake pan and cook for ~30-40 minutes (ovens vary so test with a toothpick in the center and remove when it comes out clean) 350 F – make sure a toothpick comes out clean

Set aside to cool

Set in the fridge until cooled but not hard

When all components are ready, start by placing a chocolate cake layer on your plate or cake stand. Then place a piece of the set mousse on top (we like to flip it so the mousse is touching the cake layer and the plastic wrap side is facing up. We then slowly peel off the plastic wrap). Repeat this another time and place the final cake layer on top

After the cake is stacked, we gently go around the mousse layer with a spoon to carve our a slight indent. It should be about a half inch deep (This will get filled with icing and keeps the mousse inside the cake)

After creating the indent, ice the cake with the chocolate ganache. Serve immediately or store in the fridge until ready to serve