Method

• 1.
  For pastry cream, beat yolks and sugar until pale. Sift in flour, whisking to combine. Place milk in a pan and bring to scalding point, then add to egg mixture.
• 2.
  Turn heat to low and return mixture to pan, stirring constantly until thick. Add vanilla, then transfer to a bowl and cover with plastic wrap. Refrigerate to chill.
• 3.
  For bomboloni, place yeast in a small bowl with 1 tablespoon each of sugar and flour. Stir in warm milk. Set aside in a warm place for 15 minutes until mixture bubbles and froths.
• 4.
  Place remaining sugar and flour in a bowl with rind and butter, then add yeast mixture. Using your hands, combine mixture, then turn onto a floured board.
• 5.
  Knead for 5 minutes until smooth and elastic, then place in a lightly oiled bowl, cover with a clean tea towel and set aside in a warm place to rise for about 2 hours.
• 6.
  When dough has nearly doubled in size, punch it down with your fist. Use a rolling pin to roll out dough on a lightly floured surface to about 1cm thick. Use a 4cm pastry cutter to make 24 rounds and place on a baking tray (allowing a little room to expand). Cover with a tea towel and set aside to rise for another hour.
• 7.
  Heat oil in a deep-fryer or heavy-based saucepan and heat to 180°C. (If you don't have a deep-fryer thermometer, test a cube of bread - it should turn golden in about 2 minutes.) You don't want oil too hot, as the bomboloni will darken before the inside is cooked, so adjust heat if necessary. Fry, 3 or 4 at a time, until golden. You may need to turn with tongs. Remove with tongs or a slotted spoon and drain on paper towels. While still warm, roll in extra sugar. Cool completely.
• 8.
  Just before serving, use a sharp knife to make a slit in the bomboloni and pipe or spoon in the pastry cream filling.