First, prepare the layers. Separate the egg yolks from the whites. Beat the whites to a thick foam. Beat the yolks until pale yellow and fluffy, then add the sugar and warm water to them. Beat another 3 min. or so, pour in the flour, cocoa and baking powder. Beat another 3 min.
Start adding the beaten whites spoon by spoon, while stirring with slow, gradual movements with the spoon.
Cover a rectangular oven dish with baking paper and smear it with oil. Pour in 1/2 the mixture on top and distribute it everywhere with a spoon to obtain a very thin layer.
Bake in a preheated 356°F (180 °C) oven, while being careful not to bake the layer too much - it needs to remain soft. Bake the 2nd layer from the remaining mixture in the same way.
For the cream filling, dissolve the gelatin in the water and leave it to swell, then heat it on a water bath until it melts. Next, beat the cream with the powdered sugar and once you obtain a fluffy consistency, pour the gelatin in it and stir very well.
Once the cake layers are ready, smear one with 1/2 the cream mixture, then pour the chocolate filling on top and distribute it with a spatula. Put in the fridge for 5 min. for the chocolate filling to harden.
Next, take it out of the fridge and distribute the remaining cream filling over the chocolate one, smoothing it out well. Place the 2nd cake layer on top.
For the glaze, melt the chocolate, butter and oil in a water bath and pour it over the dessert. Smooth it out and finish forming it. Put in the fridge for 4-5 hours to harden well. Cut the dessert into rectangles before serving. It's best to store the dessert in a cold fridge.