Berlin Balls for New Year's Eve
Dissolve the yeast with the sugar into the milk. Mix the yeast mixture with the flour, egg yolks, butter, salt and lemon zest, and knead with the dough hook of the hand mixer to a soft dough. Knead until the dough leaves from the bowl edges. Cover with cloth and let rise in a warm place until the volume has doubled.
Knead the dough on a floured surface vigorously. Divide into half and shape into rolls. Cut each half into 6 equal pieces, shape each piece into balls, and let rise for about 30 minutes.
Fry the dough balls in portions in hot oil (180°C) (175°F), turning once, for about 1-2 minutes per side.
Remove the balls with a skimmer from the oil, drain on paper towels, and let cool slightly. Fill a pastry bag (with a long, thin spout) or a cake syringe with the apricot jam and inject into the fried balls.
Dust the fried balls with powdered sugar and serve immediately.