01 -
Check the instructions on your yeast packet. Some yeast can be added straight to the dry ingredients (as in this recipe) and others need to be activated in lukewarm liquid first. If activation is needed, use a small amount of the lukewarm milk (don't add extra liquid).
02 -
Put the flour, sugar and yeast in the mixer bowl and stir to combine. Scatter cubes of butter over the flour so it's evenly distributed, then pour in the eggs, lukewarm milk, vanilla and salt. Attach a dough hook to the mixer and knead on a low speed for 10 minutes (on a KitchenAid mixer use speed 2). After 10 minutes the dough should be smooth, elastic and slightly tacky.
03 -
Tip the dough onto a clean work surface (no extra flour needed) and shape it into a smooth ball by kneading it 2-3 times. Place the dough in a clean bowl lightly greased with oil and cover with plastic wrap. Leave to prove for 2-3 hours or until tripled in size.
04 -
Once the dough has risen, tip it out onto a clean work surface, knock out the air, then knead it a few times back into a smooth ball. Flatten the dough with your hands then roll it out into a rectangle 1/2 inch (1.5cm) thick. Use a cookie cutter or glass to cut out round doughnuts about 3.5 inch in diameter. You can cut the scraps into random shapes for frying or re-knead and roll out again to cut more doughnuts.
05 -
Place the cut out doughnuts on a surface lined with baking parchment and cover loosely with plastic wrap. Leave to prove for 1-1.5 hours or until tripled in size.
06 -
While the doughnuts are proving, make the pastry cream. Put the egg yolks, sugar, vanilla and lemon zest in a large bowl and whisk until well combined. Add the cornstarch and whisk again until well combined. Heat the milk in a saucepan until hot, then turn off the heat and let it sit for 1 minute. Slowly pour the milk into the egg mixture while constantly whisking so the eggs don't scramble. Pour the mixture back into the saucepan and heat on low while constantly stirring until thick and creamy (about 10-15 minutes). Once thick, turn off the heat and pour into a clean bowl. Place plastic wrap directly over the pastry cream so a skin doesn't form and leave to cool.
07 -
When ready to fry, heat a large deep pan or pot of oil to 170°C/337°F. Cut the parchment paper into squares so each doughnut is on an individual square. Carefully drop the doughnuts into the oil and immediately remove the parchment paper with tongs. Fry in batches to avoid overcrowding. Fry for 2 minutes, then turn over and fry for another 2 minutes. Remove and drain on kitchen paper for around 2 minutes, then roll in sugar. Leave to cool before filling.
08 -
To fill the bomboloni, insert a small knife into the side of a doughnut and move it around to make a small incision. Fill a piping bag with the pastry cream or desired filling and pipe it into the doughnuts. Serve immediately for best results or store in plastic containers for 1-2 days.