Start by making the meringues; alternatively, if you wish to skip this process, you may use store-bought ones.
In the bowl of a stand mixer, place the egg whites, ensuring they have reached room temperature. Whisk at medium speed until quite fluffy, gradually incorporating the granulated sugar while the mixer is running. Once a rich meringue has formed, add the icing sugar and baking powder, and continue mixing. Finally, two minutes before stopping, add the vinegar.
Using a piping bag or a spoon, form the meringues on parchment paper; you will need two baking trays. Bake at 160°C for approximately 20 minutes. The goal is for them to be chewy on the inside and crunchy on the outside.
For the caramelized hazelnuts, place the nuts on parchment paper and prepare the caramel. In a non-stick frying pan, heat half the amount of sugar until it turns into caramel. Once melted, add the remaining half and let it caramelize as well. Carefully pour the caramel over the hazelnuts so they are all covered and allow them to cool completely.
For the cream, pulse the Olympus Cocoa Halva in a food processor with a few drops of water until it becomes a smooth paste. In the mixer bowl, whisk the vegetable heavy cream until it becomes fluffy whipped cream. While the mixer is running, gradually add the pureed halva by the spoonful and wait for it to be fully incorporated. Incorporate the sweetened condensed milk in the same manner. Once a rich cream has formed, remove the bowl from the mixer.
In the same bowl, add the meringues, breaking them into pieces by hand. If you wish, keep a few aside for decoration. Add the dark chocolate and half of the caramelized hazelnuts (after crushing half of them into small pieces). Keep the rest for garnishing.
Mix the entire mixture well. Line a cake tin (either round or rectangular) with plastic wrap and pour the mixture in. Cover again with plastic wrap and place in the freezer for at least 5 hours. Unmold, decorate with the reserved meringues and caramelized hazelnuts, and enjoy.