Beat the confectionery cream in a bowl with a mixer until it forms soft tips. Add the chocolate spread and stir with a fork until you get a homogeneous mixture.
Combine sugar and water in a 1:1 ratio, stir until it melts and add 1 tbsp sour cherry liqueur. Place the 1st cake layer in a plate, syrup it lightly with the sugar syrup.
Smear with part of the chocolate cream on top. Place the 2nd cake layer, syrup, cream and the final cake layer, smeared with the remaining cream. Peel the mandarins and divide them into pieces.
Decorate the cake with the mandarins, sprinkle chocolate sprinkles in the middle, sprinkle ground hazelnuts, grated white chocolate. Once cooled, slice into pieces and serve.