Polish babka

Method
Prep:30min  ›  Cook:1hr  ›  Extra time:2hr rising  ›  Ready in:3hr30min 

1. Warm the milk in a small saucepan until it bubbles, then remove from heat. Place 5 tablespoons flour in a large bowl and pour milk over flour. Beat until smooth. Let cool until lukewarm. In a small bowl, dissolve yeast and sugar in warm water. Pour into cooled milk and beat well. Let prove in a warm place until bubbly.
2. Stir 2 eggs, egg yolks, butter, vanilla and lemon zest into milk/yeast mixture. Mix in flour, about 125g at a time, beating well after each addition. When a loose dough has formed, turn out onto a lightly floured surface and knead until smooth, about 10 minutes. Gently knead in raisins.
3. Lightly oil a large bowl, place the dough in the bowl and turn to coat with oil. Cover with a damp cloth and let rise in a warm place until doubled in volume, about 45 minutes. Deflate the dough and let rise again until doubled in volume, about 30 minutes.
4. Deflate the dough and turn it out onto a lightly floured surface. Divide the dough into three equal pieces and form into round loaves. Place the loaves into well buttered tall, round baking tins (panettone tins work well). Do not fill the tins more than 1/3 full. Cover the tins with a damp cloth and let rise until tripled in volume, about 40 minutes. Meanwhile, preheat oven to 190 C / Gas 5.
5. In a small bowl, beat egg with 2 tablespoons water. Lightly brush this mixture onto the risen loaves. Bake in preheated oven 10 minutes. Reduce oven temperature to 170 C / Gas 3 and bake for 30 minutes more. Reduce oven temperature to 140 C / Gas 1 and bake for another 15 to 20 minutes, until golden brown.
6. Let loaves stand 5 to 10 minutes before removing from tins. Transfer loaves very gently onto a cloth-covered pillow (never a hard surface as this may cause the babka to settle or fall). Change position of loaves during cooling to cool evenly.