Hazelnut Chocolate Filled Cake

To prepare the hazelnut and chocolate filled cake, start by pouring the whole eggs and sugar into the bowl of the stand mixer (you can use electric beaters and a large bowl as an alternative) 1. Add the yolks 2 and a pinch of salt 3. 

Beat for at least 10 minutes or until the mixture is light and fluffy 4. Meanwhile, sift the flour and potato starch into a bowl 5 and add the cocoa powder 6. 

Gently mix with the whisk to blend the mix 7. By now, the egg and sugar mixture should be fluffy, you can test it by lifting the whisk to see if it forms ribbons 8. Then add the dry ingredients in two batches 9. 

This way you can mix with the spatula, making gentle movements from the bottom to the top and avoiding lumps 10. Then add the second part of the mixture 11 and obtain a smooth batter 12.

Transfer it into a greased and parchment-lined 10-inch springform pan 13, level the surface and bake in a preheated static oven at 350°F for about 30-35 minutes; check doneness with a toothpick 14. Let it cool completely when done 15.

Prepare the soaking syrup. In a saucepan, pour water and sugar 16, stir and bring to a boil 17. Then turn off the heat, let it cool and then add the rum; the syrup is ready 18.

Now take care of the filling. In a bowl, pour the mascarpone, hazelnut cream 19 and powdered sugar 20, work with the spatula to blend 21.

Soak the gelatin in cold water for 10 minutes 22. Heat the milk in a saucepan, add the previously soaked and squeezed gelatin 23, turn on the stove and stir until it dissolves 34, then turn it off and let it cool for 5 minutes.

Now whip the fresh cream with electric beaters 25. Pour the slightly cooled milk into the mascarpone and hazelnut mixture 26, mix well 26 and then add the whipped fresh cream, fold gently with movements from the bottom to the top 27.

Set aside in the refrigerator 28 and take the now cold cocoa sponge cake. Cut off the dome 29 and halve the cake 30.

Brush with the soaking syrup 31 and fill with slightly more than half of the cream that you have placed in a piping bag 32. Spread to level 33.

Take the second disk, soak 34 and flip onto the filled part 35, then soak the top: place in the refrigerator and take care of the glaze 36.

Heat the cream in a saucepan 37, when it reaches a boil, turn off the heat and add the chopped chocolate 38. Stir until completely melted 39.

When the ganache reaches a temperature of about 122°F, pour it over the cake 40 and shake the rack to level the coating 41. Finally, garnish with hazelnut crumbs all around 42.

Transfer the cake with two spatulas onto the serving plate and allow the glaze to set in the fridge, about half an hour 43. Transfer the remaining cream into a piping bag with a star nozzle and pipe dollops for decoration 44. Your hazelnut and chocolate filled cake is ready 45.