Separate the egg whites from the yolks. Mix the egg whites with the salt powder. Add the ground sugar in two slices and mix after each slice until the sugar is completely dissolved and the foam formed is dense and glossy.
Add the yolks and oil to the composition and mix until incorporated.
Mix the flour with the cocoa and sift the mixture into two or three slices. It is easily embedded with a spatula, in circular motions, from top to bottom.
Pour the composition into a rectangular tray (35 x 25 cm) lined with baking paper and place in the preheated oven at 180 degrees C for 30-35 minutes, or until the toothpick test passes.
Remove the tray from the oven and allow it to cool completely, then cut the top in half horizontally.
Put the cleaned and sliced apples in a double-bottomed saucepan. Add water, sugar and lemon juice, mix well, put a lid on top and leave the pot on the right heat for 10 minutes, or until the apples are soft. After cooling the apples a little, turn them into puree with a vertical mixer, then leave the puree to cool.
Hydrate 5g of gelatin in 25ml of cold water for 10 minutes, then dissolve in a steam bath, according to the instructions on the envelope.
Mix the cream and liquid cream with the ground sugar until it increases in volume and becomes aerated. Add 500g of apple puree and mix. Take half of this composition and place in another bowl and add the dissolved gelatin and mix until incorporated.
Place the first slice of countertop in the tray in which it was prepared (lined with baking paper), syrup, add apple cream (first part), spread evenly, put in the refrigerator for at least 15-20 minutes.
Hydrate the gelatin in 50ml of cold water for 10 minutes, then dissolve in a steam bath, according to the instructions on the envelope. Incorporate with a mixer into the remaining apple puree (500g).
Remove the tray from the fridge and pour the jelly over the apple cream and leave in the fridge for 20-30 minutes.
Prepare the second slice of apple cream. Hydrate 5g of gelatin in 25ml of cold water for 10 minutes, then dissolve in a steam bath, according to the instructions on the envelope and add the gelatin over the remaining apple cream.
Remove the cake pan from the fridge and pour in the apple cream, spread well and place the other slice on the countertop (don't forget to syrup it after you put it on) and put it in the fridge for at least 5 hours (or over night).
After the creams have hardened, take the cake out of the fridge, portion it. Mix the liquid cream with the sugar until it gains volume and becomes aerated. Put the cream in a saucepan and garnish each cake.