1) Preheat the oven to 180C / 160C fan.  Line two 20cm (max22cm) round cake tins with parchment paper.

2) Beat the butter with the sugar and the lemon zest until light and fluffy. In a separate bowl, whisk the eggs whites until soft peaks form.

3) Add the egg yolks and the lemon zest to the butter mixture and mix these in. Add the soured cream and mix again. Sift both the plain and the wholemeal flour, then add these into the butter mixture together with the bicarbonate of soda and the baking powder and mix. Next, gently fold in the whisked egg whites (in two batches).

4) Divide the batter between the cake tins. Place the tins into the preheated oven, then immediately lower the temperature to 175C / 155C fan and bake for about 30 – 40 minutes. Check the cake for doneness performing the skewer test. Once baked, remove the cakes from the tins and let them cool.

5) In the meantime, prepare the vanilla pastry cream. Pour 400ml of the milk into a medium saucepan, add the vanilla; and start warming it up on a medium high heat. In a bowl, mix the egg yolks with the remaining milk, sugar, salt, flour and the cornflour. Once the milk has just come to a boil, take it off the heat and start pouring it in a slow steady stream into the egg yolk mixture, whisking constantly so that the eggs don’t scramble. Return the mixture to the saucepan and cook for a couple of minutes over medium heat, again whisking constantly. Take the saucepan of the heat, transfer it into a heatproof bowl, cover with cling film and let it cool completely.

6) Once cooled, whisk the butter, then slowly whisk in the pastry cream until smooth and creamy.

7) Split each cake into three equal layers. Spread the jam on the first cake layer, cover with the second cake layer and pipe on some vanilla pastry cream.

8) Take three cake layers and using a large 10cm round cookie cutter, cut out the middle part of the cake (you will have three cake layers with a hole in the middle of each).

9) Cover the second cake layer with a cake layer with a hole in the middle, and pipe some more vanilla cream on it. Make sure not to pipe any cream into the actual hole. Add the remaining two layers with a hole, adding more vanilla pastry cream on each layer as you go along. Before you add the last cake layer (this will be a whole layer), add the chocolate eggs into the hole that’s been created in the middle of your cake. Cover with the last cake layer, spread some jam on the top of the cake, then add the remaining vanilla pastry cream and cover the whole cake with it (top and the sides).

10) Decorate the cake to your liking. Slice and serve. Enjoy!