Place all the ingredients on the worktop/ kitchen table well before the start of your doughnut-making. The products must be at room temperature. Prepare the leaven of yeast with 1/2 a cup of warm Łaciate milk 3,2% fat, a tablespoon of sugar and a tablespoon of flour. Leave to rest in a warm place for 30 minutes. Melt Łaciate extra butter in a saucepan. Beat the egg yolks with sugar and, optionally vanilla sugar, in a bowl. Slowly and gradually, combine the mixture with cooled melted Łaciate extra butter, flour and the leaven mixture. Add a dash of salt.
Knead the dough for a few minutes and form it into one smooth ball. Then set aside to rise for about another 30 minutes. After this time, roll out the dough into a layer of about 1 cm thick.
Use a brim of a glass or a cookie cutter and cut out circles. Place a portion of the confiture in the middle of each circle – but not too much, otherwise your doughnuts will not seal well. Join two yeast circles and seal their edges together to form a shapely ball. You can also divide the dough into portions, flatten slightly with your hand, place the confiture in the middle and form equal-sized balls. When all doughnut balls are ready, cover them with a tea towel and leave in a warm place to prove.
Place a large pan over a high heat, pour in the lard or oil and allow to heat up. When it is hot, reduce the heat and drop the pieces of dough into the pan in batches. Fry on both sides until golden. Take out the fried doughnuts and drain from excess fat. Serve with a dash of caster sugar or decorated with icing, which you can prepare from powdered sugar and a small amount of hot water (it should be thick).