Heat 200ml liquid cream to near boiling point. Turn off the heat and add 200g of broken chocolate pieces and mix well. Allow to cool completely and refrigerate for a few hours (or overnight).
For the top, place the cocoa in a bowl and pour the boiling water, stirring constantly, until smooth, then leave to cool. Strain the composition so that it does not remain cocoa lumps.
Beat the egg whites hard with a pinch of salt. Add half the amount of sugar and mix until you get a glossy meringue, which makes spikes when you remove the blades from the mixer. Rub the yolks with the other half of the sugar until they become white and creamy. Gradually add the oil, rum essence, then the cooled cocoa composition. Incorporate the flour mixed with baking powder and at the end, in 2-3 installments, the meringue.
Pour the composition into a tray (28 cm in diameter) lined on the bottom with baking paper and grease the edges with butter. Place the tray in the oven over medium heat for about 40 minutes, until the top becomes firm to the touch. Remove to a grill and leave to cool. After it has cooled completely, cut the top into two discs.
Put the raspberries in a pot, add the sugar, water and simmer for 5-10 minutes. Put in a sieve and grind with a fork, then press to drain the juice. Allow the resulting juice to cool completely.
Mix the liquid cream.
Separately mix the mascarpone with the sugar, then add the liquid cream and mix well.
The gelatin is hydrated in 50 ml of cold raspberry juice, and after 10 minutes it melts in a bain-marie. Mix the gelatin with the raspberry juice and then add over the mascarpone cream and mix.
Place the first countertop on a plate and place the adjustable cake ring around it. Pour half of the raspberry cream and place the second top on top. Pour the rest of the raspberry cream over the counter and put the plate in the fridge for 2 hours.
Remove the chocolate cream from the cold and mix well. Separately mix the cream (not too hard) and add over the chocolate cream and mix.
A sharp knife (previously passed through hot water) is passed around the edges of the cake. The ring around the cake then comes off.
Cover the edges of the cake with chocolate cream and decorate the cake according to your imagination.
Fill the ice cream cone with chocolate cream and place on the cake. Sprinkle the ornaments and place the chocolates.
Melt the chocolate (10g) in the microwave, put it in a bag, cut a corner and decorate the croissant.