Do this at least several hours before starting the cake for best results, or up to several weeks.

Drain the cherries through a sieve, then add them to a jar. Add sugar and 1/2 cup of liquor, then add enough of the drained cherry juice to barely cover the cherries. Gently mix until the sugar is dissolved, cover with a lid, and refrigerate.

Then, on the day of making the cake, drain the cherries through a sieve, reserving the cherry syrup. Pick out about 14 best-looking cherries and set them into a cup, this will be used as decoration of the cake. Set everything aside.

Bake a double recipe of the Chocolate Sponge cake in one round 8"x3" baking pan.

Once cool, with a long serrated knife cut a thin layer (~ 1/2 inch thick) off the top and bottom of the cake, this will serve as the top and bottom of the cake, later.

Then, cut out the inside of the middle layer, leaving only about a 1/2 inch thick "ring" of the cake layer.

Cut the cut-out inside of the middle layer into small cubes and set aside.

While the Chocolate Sponge Cake is baking make the cream.

Whip room temperature butter for about 5 minutes, scraping down the sides several times throughout.

Then, add dulce de leche in 2-3 additions, whipping in between.

Lastly, fold in a splash of vanilla and sour cream until fully incorporated.

Fill the empty dulce de leche can with cream and set aside.

Add the cubed cake pieces to the remaining prepared cream, sprinkle with 1/4 cup of the cherry liquor syrup, and mix until a uniform mixture forms.

Add the drained cherries and carefully fold them in.

Put a dab of frosting onto the serving platter and top with the top layer, top side down. Press to adhere.

Brush on a generous amount of the cherry syrup and liquor mixture drained from the cherries.

Spread about 1/4 cup of frosting over the cake.

Set the middle cake "ring" section of the cake on top and gently press to adhere. Brush some of the soaking syrup on the inside of the cake ring, then cover the inside with a thin layer of the reserved cream.

Fill the inside with 1/2 of the prepared filling, then using a vegetable peeler shave some chocolate on top. Cover with the other half of the filling and spread into an even layer.  Gently press the filling in until the ring is full. If there's any leftover, consider it your sample and enjoy :D.

Spread another 1/4 cup of frosting on the cut side of the last remaining cake layer. Top the filled cake with this layer, frosting side down.

Brush on a generous amount of the cherry syrup on top of the cake.

Cover the cake with a plastic wrap, then fit a cake ring or the baking pan that Chocolate Sponge Cake was baked in over the top of the cake. This will keep the cake from falling apart as it sits in the fridge.

Refrigerate for at least 4 hours or overnight.

Make 1 recipe of chocolate ganache (or you can also make chocolate glaze from this recipe (Note 1)) and let it cool slightly until it is slightly thickened.

While it is cooling, remove the cake from the fridge, remove the cake ring and plastic. Then cover the cake with the remaining frosting and make the covering as smooth as you can.

Place a cooling rack or a bowl over the baking sheet, then place the cake on top. Make sure the baking sheet is larger than the cake to catch the chocolate glaze drippings.

Pour the chocolate ganache over the cake and spread it until it covers the sides of the cake. Use a spatula dipped in hot water, then wiped dry to patch up any mishaps. Leave the cake undisturbed for at least 10 minutes before moving the cake to ensure that the chocolate stays smooth and without ripples.

Using a vegetable peeler go along the rib of a chocolate bar to shave chocolate right over the top edge of the cake (Note 2). Then, add the reserved cherries to the edge of the cake as well.

Refrigerate the cake overnight to 48 hours or until ready to eat. Remove from the fridge about an hour before eating.