Vertical chocolate cake with yoghurt souffle

Have you ever thought about the day, when someone decided that all the cakes have to be round in their shape? Why should the layers be laid horizontally? The cake we offer you today, proves that you don't have to follow the standard rules to make a delicious chocolate berry cake! Yoghurt soufflé, juicy berries and perfect chocolate sponge cakes… It’s time to experiment!

1. Divide the eggs into whites and yolks and leave them for 25 to 30 minutes at the room temperature.
2. Mix the flour with the baking powder and cocoa, and sift.
3. Divide the sugar into 2 parts: 100g (3.55 oz) and 25g (0.85 oz). Whisk the yolks with sugar (100g | 3.55 oz) and vanilla extract in a deep bowl, whip until fluffy and lightened (for 3 minutes).
4. Add the flour mixture and knead the dough with a spatula until smooth (do not stir too much!). In a separate bowl, whip the egg whites until fluffy, smooth foam; add the sugar (25g | 0.85 oz) and whip until stable dense peaks.
5. Add a third of the meringue to the bowl with the yolks and whisk with a mixer on a slow speed until smooth. Gently pour the resulting mass into a bowl with the remaining meringue and knead the dough, using a spatula, with wide circular movements.
6. Preheat the oven to 200C (392F). Cover the baking sheet with the parchment. Also cover a split mold (16 cm | 6.3 inch) diameter with the parchment, without greasing it. Pour 5 mm (0.2 inch) of the dough on the bottom of the mold. Spread the rest of the dough evenly over the baking sheet. Smooth it and lightly hit the work surface a couple of times. Separately bake it for 10 to 12 minutes. The finished biscuit should not stick to your hands.
7. Remove the biscuit from the oven and cool. Then pour the surface of the biscuits with cocoa, using a sieve; cover them with a new sheet of parchment and turn them over. Remove the bottom sheet of parchment and leave at room temperature until assembling the cake.

1. Soak the gelatin in cold water for 10 to 12 minutes.
2. Cool the yogurt, the cream (200g | 7.05 oz) and the condensed milk. Put them in a deep bowl and whip with a mixer, gradually increasing the speed, until thick and dense.
3. Wash the berries and dry them with a paper towel.
4. Heat the smaller part of the cream (115g | 4.05 oz) to 75-80C (167 to 176F); remove it from the heat, and add the swollen and squeezed gelatin into it. Stir and cool slightly.
5. Pour the creamy gelatinous mass into the whipping cream in a thin stream, whisk at a low speed for another minute. Put the resulting soufflé in the fridge, stirring occasionally so that the soufflé stiffens slightly.

Whisk all the ingredients cold at a medium speed of the mixer until smooth. Stir them additionally with a spatula. Cover the chilled cake with that custard.

1. Cut the sides of the biscuit evenly; cut them into two equal parts along the long side.
2. Spread a layer of a cling film on the work table, twice as long as the length of the biscuit. Put the first half of the sponge biscuit (cocoa side down!). Evenly spread a third of the cooled creamy soufflé on it. Smooth the soufflé, and place the berries at random. Roll up on the SHORT side, and set aside.
3. Cover the second part of the sponge biscuit, and continue folding, placing the edges of the biscuits butt to each other.
4. Wrap the roll in a film (carefully, but with effort), and place it vertically on the stand. Place the cake in the freezer for 2.5 to 3 hours. Leave the rest of the soufflé at the room temperature in a cool place.
5. Place the round part of the sponge cake on the stand. Spread approximately 1 tbsp. of soufflé and place the cake freed from the film on top. Cover the sides and the top of the cake with the remaining creamy soufflé, and smooth. Put the cake in cold to stabilize overnight.
6. Cover the cake with the finishing custard; align and decorate.