Preheat the oven to 350 degrees F (180 degrees C).
For the cake: Spray a 10 inch round cake pan with baking spray, or brush it with melted butter and then sprinkle with flour. Line the bottom of the pan with parchment paper and spray it with baking spray too.
Melt the chocolate for the cake and for the frosting over a double broiler. I use a glass bowl set over a small saucepan with about an inch of water in the saucepan.
Whisk until the chocolate melts. Set aside to cool.
Cream Butter (14 tablespoon) and half of Granulated Sugar (3/4 cup) for the cake on high speed in a standing mixer with a paddle attachment or a hand mixer until light and fluffy.
Separate the Egg (8) yolks and egg whites. Save egg whites in a small bowl for later. Add in the 8 egg yolks.
Mix until combined.
Add melted Chocolate (7 ounce) to the bowl.
Mix until combined.
Whisk the All-Purpose Flour (1 1/2 cup) with Baking Powder (2 teaspoon).
Add the dry ingredients to the cake batter and mix just until it's combined. It is ok if there are a few streaks of flour left. You can finish mixing it later with a rubber spatula.
Whisk the eggs whites until they are foamy, gradually add the remaining half of sugar. Keep whisking until stiff peaks form.
Gently fold it into the cake batter. Be careful not to deflate the batter too much.
Pour 1/3 of the batter into the prepared cake pan.
Bake for 15 minutes, or until the cake is nice and springy when you touch it, or when a toothpick comes out clean. Slice the cake in half horizontally.
Repeat and pour the next 1/3 of the batter into the prepared cake pan and bake for 15 minutes and slice when finished.
Repeat for the last 1/3 of the batter and bake for 15 minutes and slice, for a total of 6 cake layers.
For the syrup: In a small saucepan, combine the Water (1/2 cup), Granulated Sugar (1/3 cup), and Chocolate Liqueur (1/2 cup) and cook over medium-hot heat until the sugar melts. Remove from the heat and let cool.
For the frosting: Add the Cream Cheese (8 ounce) and Sweetened Condensed Milk (1 can) in a standing mixer with a paddle attachment.
Cream the ingredients.
Add the other half of the melted Chocolate (6 ounce) and Chocolate Liqueur (2 tablespoon). Mix until well combined.
In another chilled bowl and whisk attachment, whisk the Heavy Cream (1 cup) until peaks form.
Gently fold it into the rest of the frosting.
The frosting should look like this.
Assembling the cake: Line the edges of a round cake platter with aluminum foil or parchment paper.
Brush the top of each cake layer with the syrup.
Spread the frosting on each of the cake layers.
Smooth the frosting over the sides and top of the cake.
Completed frosting should look like this.
Dust surface of the cake with Unsweetened Cocoa Powder (3 tablespoon) and place the Chocolate Truffles (12) around the edges of the cake.
Here is a picture of the final cake assembled.