• Dissolve 42 g fresh yeast in 100 ml milk (lukewarm) with 1 tsp sugar. Let stand for 10 minutes until it starts to foam. In a large bowl, mix 500 g all-purpose flour with 1.5 tsp salt.

  In a separate bowl, beat 2 eggs with 50 g sugar until light and fluffy. Add 100 g butter, 2 tbsp rum, zest of 1 lemon and 1 tsp vanilla extract.

  Make a well in the flour and pour in the yeast mixture and the egg mixture. Add 150 ml milk.
• Knead with a stand mixer (or by hand) until a smooth dough forms. This takes about 8-10 minutes. The dough should be soft and elastic but not sticky. Form the dough into a ball and place it in a greased bowl. Cover with plastic wrap and a tea towel and let rise for 1 hour in a warm place (24-27°C) until the dough has doubled in volume.
• Gently press the dough on a lightly floured surface and roll out to 2 cm thickness. Use a round cutter of 7-8 cm diameter to cut circles out of the dough. Place them on baking sheets lined with parchment paper.

  Loosely cover the krofne and let them rise for another 30-45 minutes until they are airy and about 1.5 times larger.
• Heat sunflower oil in a large pan or deep fryer to exactly 170°C. It is important to maintain this temperature constantly for the best result.

  Fry the krofne in small batches, about 2 minutes per side until golden brown. Make sure the oil does not get too hot, otherwise they will become too dark on the outside and remain raw on the inside.

  Drain on kitchen paper and let cool completely.

For filling:

• Warm jam slightly in the microwave and fill the piping bag. Make a small hole on the side with a small nozzle and carefully fill until the krofne feel just full.
• Sprinkle generously with icing sugar just before serving.