Step 1

Put the flour, sugar and yeast in the mixer bowl and stir to combine.

Step 2

Scatter cubes of butter over the flour so it's evenly distributed then pour in the eggs and lukewarm milk, vanilla and salt.

Step 3

Attach a dough hook attachment to the mixer then knead on a low speed for 10 minutes (on a KitchenAid mixer I use speed 2).

Step 4

After 10 minutes the dough should be smooth, elastic and slightly tacky (see recipe notes 1 & 2 if using cups it's important).

Step 5

Tip the dough out onto a clean work surface (you don't need any flour and extra flour should be avoided if possible). Shape the dough into a smooth ball by kneading it 2-3 times.

Step 6

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.

Step 7

Once the dough has risen, tip it out onto a clean work surafce, knock out the air then knead it a few times back into a smooth ball.

Step 8

Flatten the dough with your hands then roll out on into a rectangle ½ inch (1.5cm) thick.

Step 9

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 them and roll out again to cut out more doughnuts.

Step 10

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.

Step 11

While the doughnuts are proving, make the pastry cream and leave to cool (directions below).

Step 12

When ready to fry heat a large deep pan or pot of oil until it reaches 170°C/337°F.

Step 13

Cut the parchment paper into squares so that each doughnut is on an individual square of parchment.

Step 14

Carefully drop the doughnuts into the oil and immediatley remove the parchment paper with tongs. It's best to fry the doughnuts in batches and not overcrowd the pan.

Step 15

Fry the doughnuts for 2 minutes then turn over and fry for another 2 minutes on the other side.

Step 16

Remove and drain on kitchen paper for a around 2 minutes then roll the doughnuts in sugar. Leave to cool before filling.

Step 17

To fill the bomboloni insert a small knife into the side of a doughnut and move it around to make a small incision.

Step 18

Fill a piping bag with the pastry cream or desired filling and pipe it into the doughnuts.

Step 19

Serve immediately for best results or store in plastic containers for 1-2 days.

Step 20

Put the egg yolks, sugar, vanilla and lemon zest in a large bowl and whisk until well combined.

Step 21

Add the cornstarch and whisk again until well combined.

Step 22

Heat the milk in a saucepan until hot then turn off the heat and let it sit for 1 minute.

Step 23

Slowly pour in the milk into the egg mixture while constantly whisking so the eggs don’t scramble and there are no lumps.

Step 24

Pour the mixture back into the saucepan and heat on a low heat whilst constantly stirring until thick and creamy (about 10-15 minutes) the mixture needs to be very thick. Don’t be tempted to turn up the heat or the eggs will scramble.

Step 25

Once thick, turn of 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.