Add yeast to 85% of the milk and stir the egg in. Add the flour and lemon zest. Knead the dough with a kitchen mixer.

Add the leftover lukewarm milk little by little to the dough. Add the melted butter and salt and knead the mixture for another 15 minutes with a mixer.

Stir the raisins, sultanas and apple cubes carefully into the dough.

Cover the dough with a moist cloth and let it rise for 30 to 45 minutes in a warm area, around 35ºC. The temperature of the dough should be 28ºC.

Scoop the dough well after it has risen. Let stand for another 5 minutes. Heat the oil to 180ºC.

Scoop the dough with two spoons (or an ice cream spoon) to make balls and place in the oil. Deep fry for 6 minutes and turn around halfway. Remove from the oil when they are golden brown. Smaller balls are done after 3 minutes of deep frying. Rest on kitchen paper and sprinkle with powdered sugar once cooled down.