Heat the milk until warm to the touch and add the quick action yeast with a tsp of sugar.

Whisk well and leave for 15 minutes until the yeast has activated and a froth has formed on top of the milk.

Mix the dry ingredients in a large bowl and make a well in the middle. pour in the melted butter and eggs (beaten) followed by the activated yeast and milk.

Stir together until a wet sticky dough has formed.

Let this sticky dough rest for 10 minutes.

Lightly oil your hands and work surface.

Tip the dough out on to the work surface and knead for 10 minutes until the dough becomes smooth and elastic.

Transfer the dough into a new, lightly oiled bowl and let prove for 2 hours or until it has doubled in size.

Put the egg yolk in a saucepan with the cornflour, sugar and seeds from the vanilla pod.

Whisk them together lightly before turning on the heat to low.

Slowly add the milk stirring constantly on a low heat.

Cook like this for roughly 5-8 minutes or until it is smooth, thick and glossy.

Remove the custard from the heat and allow to cool completely.

Next, cut the dough into 10-12 balls just smaller than a tennis ball.

Knead for a further 5 to 10 minutes and shape into circular disks.

Place these on a lightly oiled plate and let rise again for a further 45 minutes or until doubled in size again.

Heat your oil to 160C.

Once the temperature has been reached, fry each doughnut for 2 minutes on each side until crisp and golden.

Turn the doughnuts out on to kitchen roll to remove excess oil then roll in caster sugar and place to one side to cool down.

Repeat until all of the doughnuts have been cooked and coated in sugar.

Once the custard and doughnuts are both cool, fill an icing bag complete with bismark nozzle with the custard.

Push the nozzle deep into the doughnuts and fill generously with custard.