In a mixer bowl, pour the eggs and sugar and whisk on medium to high speed until the mixture turns white and creamy. Add the flour and cocoa powder and mix well with a plastic spatula.
Line the bottom of a round, detachable base 24 cm/9 ½ inch cake tin with parchment paper. Butter the paper then sprinkle with flour. Pour in the mixture and bake in a preheated oven at 180° C/356 °F (fan) for 25-30 minutes. Once baked, remove from the oven and allow to cool completely.
For the syrup:
Pour the water and sugar into a saucepan and boil for 5 minutes over medium heat. Remove from the heat, add the cognac, stir with a spoon, and set aside to cool completely.
For the meringue:
Place a saucepan over low heat, add the water and sugar, and heat until it reaches 110° C/230 °F. As soon as it reaches the desired temperature, pour the egg whites into the mixer bowl with a little salt and whisk on high speed until they become a tight meringue.
Once the above syrup reaches 125° C/ 257 °F, remove it from the heat, pour it very slowly in the meringue, beating at the same time, and continue beating for 8 more minutes, until it turns into a tight meringue. When ready, set aside.
For the cream:
Pour the 500 ml/ 2 cups of heavy cream into a mixer bowl and whisk on high speed until it becomes a thick whipped cream.
In a large bowl, pour the melted chocolate, the remaining 100 ml/1/2 cup of heavy cream and mix them with a spatula until the mixture unifies.
Then, slowly pour the whipped cream into the bowl with the chocolate, stirring with circular movements. Once the mixture is homogenized, add the meringue in batches, stirring again with gentle circular movements, with care to prevent it from deflating. As soon as it is ready, transfer to the refrigerator for 20 minutes.
Assembly:
Carefully remove the sponge cake from the mold, cut it into 3 round layers equal in thickness and brush each one well with the syrup.
Remove the cream from the refrigerator, place one sponge on a large plate, spread a little cream evenly over it, and cover with the second sponge.
Spread a little more cream evenly on top, place the third sponge cake directly on top, and brush the top and the side with the cream.
Transfer the remaining cream to a pastry bag, decorate the cake by placing maraschino cherries evenly and transfer the cake to the refrigerator for 1 hour and 30 minutes.
Remove the cake from the refrigerator, cut it into slices and serve.
Notes
1. To speed up the process, you can also use store-bought sponge cakes.2. Make sure to slowly pour the syrup so that it does not caramelize