For the starter, in a small bowl, mix flour, sugar and yeast. Add water and mix well. Cover the bowl with cling film and leave at room temperature for 60-90 minutes, the starter should begin to bubble and increase in volume. For the dough, mix sugar, salt, milk powder, butter, fat and beat with a spoon until creamy, then add eggs and add extracts (zest) and mix. Then add sourdough and flour, mix. Gradually add water as needed until the dough is very soft, pliable, not sticky or wet. If you knead the dough with your hands, it will take about 15 minutes. Transfer the finished dough to a greased bowl, cover with cling film and let rise. The dough should double in size (takes about 1.5 – 2 hours). Divide the dough into 2 parts, form 2 round rolls, grease them lightly with oil, cover with cling film and leave to rise for 2-3 hours, the dough should double in size. Carefully grease the rolls with egg grease and put in a preheated oven to 175. The recipe says that the rolls need to be baked for 50-60 minutes, my bread was baked in 45 minutes. The rolls will turn brown quickly due to the high sugar content, but they may still be raw inside – check for doneness. The color of the finished bread will be as in the photo – dark brown.