To make these very soft filled doughnuts you have to start from the preparation of the dough: pour the milk in a bowl and add the yeast crumbled with your hands. Stir well to dissolve the yeast.
Then add the sugar, seed oil and eggs. Stir again. Then add the lemon zest and vanillin, stirring constantly.
Finally add the flour a little at a time, initially with a whisk, then with your hands. Knead the dough until you get a smooth and homogeneous dough.
Place the dough in a bowl, cover with cling film without leaving any holes, and leave to rise until the dough has doubled in size.
Once it has risen, about 2 hours, take the dough and knead it with your hands for a few minutes.
Roll out the dough with a rolling pin until it is about 1.5 to 2 cm thick. With a circle mould, form some discs, I used the 4 cm diameter mould to form the "bomboloncini", but if you prefer to make real "bomboloni" use the 8 cm diameter one.
Place your discs on a baking tray and cover them once again with plastic wrap. Leave to rise for half an hour.
In the meantime, prepare the custard: pour the milk into a saucepan, turn on the flame and wait for it to boil. Personally I love to taste a more spicy cream, for this reason I decided to add the vanilla bean and a piece of lemon peel. If you prefer, you can do without, you will appreciate the individual flavours even more.
Separate the eggs, taking out only the yolks (you can use the whites to make a sensational omelette, perhaps a frothy one), and beat the egg yolks with the sugar with a whisk until the mixture is light and frothy. Then add the sifted starch a little at a time and continue to stir.
When it comes to the boil, remove the milk from the heat and take out both the berries and the cream. Using a whisk, very quickly incorporate the cream of sugar, egg and starch into the milk in the saucepan. This step must be completed quickly, otherwise the egg will cook.
Finally place the saucepan back on the heat and allow the cream to thicken over a low flame. Remember to keep stirring otherwise it will stick.
When the desired consistency is reached, divide the cream into two parts. Leave one part to rest, while the other part contains 60 g of dark chocolate cut into small pieces. Stir well so that the chocolate melts and the ingredients are combined.
Once it is ready, you just have to let it rest, then put it inside a piping bag and garnish your doughnuts.
When the doughnuts have risen, heat the oil in a frying pan and check that it is hot by testing it with a toothpick.
Fry the doughnuts until golden brown, turning them a couple of times. Then remove them with a skimmer and place them on some blotting paper.
Pour some sugar into a dish and pass in the doughnuts (they should still be warm) so that they look even more inviting.
Make a hole in the centre with the handle of a ladle, where all the delicious filling will be stored.
With the help of a piping bag, garnish the doughnuts with cream, either plain or chocolate. I personally have made them in various flavours, filling them with pistachio cream, which is immensely good, and apricot jam, my favourite.
Serve them and enjoy them while they are still hot, I assure you that they will leave every guest speechless!