Place flour, sugar, yeast and salt in the bowl of an electric mixer and stir to combine.

Add milk, egg and egg yolks. Mix with a dough hook until a sticky dough forms, and mix for another 3-4 minutes. If doing this by hand, tip the dough onto a lightly floured bench and knead for 10 minutes.

Slowly add the butter, one piece at a time, over the course of 8-10 minutes until the butter is completely combined and the dough is silky smooth.

Place dough in a bowl and cover with a damp tea towel. Leave to rise in a warm place until almost doubled in size, about 40min to an hour.

Roll the dough out on a lightly flour bench to 3cm thick. Cut out rounds using a cookie cutter (I managed to cut out 14 donuts, and my cutter was...)

Place on a baking tray lined with baking paper and leave to prove for another 10-20 minutes. The dough should feel light and fluffy when pressed, and a finger indentation should spring back slowly (if a finger print stays indented, it is over proved).

At the same time, heat the oil in a large pot to 165-75°C on a candy thermometer. Cook the donuts for 1-2 minutes on each side until golden brown. Remove with a slotted spoon onto a wire rack to drain.

Allow to cool, then poke a hole into each donut with your finger to create a cavity/space inside.

Fill a piping bag with the pastry cream you wish to fill them with, and gently fill the donut until it expands against your hand and the filling oozes out of the hole.

Spoon over the chocolate glaze or caramel sauce (heat gently in a microwave if it isn’t runny enough), and top with chopped hazelnuts and a dusting of icing sugar.

Make the creme patisserie (recipe below) and allow to cool.

If making both flavours, split the creme patisserie into 2 bowls to flavour them - otherwise just do one. The flavourings are largely to taste, with no precise measurements - just be careful not to make the cream too runny as it becomes difficult to pipe into the doughnuts.

In a separate bowl, whip the 2 cups of cream to stiff peaks.

For the nutella raspberry flavour: stir 1/4-1/2 cup of nutella into the creme patissiere. Fold in half of the cream (or all if just doing one flavour). Swirl in raspberries to taste.

For the espresso-banana-caramel flavour: stir a few tablespoons of espresso (to taste) into the creme patisserie. Add mashed banana and a pinch of cinnamon to taste. Fold in half the whipped cream (or all if just doing one flavour). Swirl in caramel sauce to taste.

Refrigerate the pastry cream until you fill the doughnuts (preferably overnight).

In a medium pot, heat the milk, vanilla and 1/4 cup of the caster sugar.

In a separate bowl, whisk the egg yolks, remaining 1/4 cup caster sugar and cornflour until pale and thick.

When the milk is at a boil, take it off the heat and slowly pour about half of it into the egg yolks while still whisking the yolks constantly.

Return the rest of the milk to the heat and pour the egg mixture into the milk, beating constantly with a whisk. Keep beating until it just comes back to the boil (it will get quite thick at this stage), then pour into another clean bowl to cool.

Cover with cling film and refrigerate (may be kept in the fridge for up to 3 days).

In a medium bowl mix together the finely chopped chocolate and icing sugar. In a small saucepan, bring the cream, vanilla, salt and butter to a light boil.

Pour the hot cream over the chocolate and let it sit for a couple of minutes without stirring. Whisk until uniform.

To make the caramel, first measure out all the components so you are ready to go (it happens quickly!).

Heat the sugar in a medium pot over medium-high heat, stirrng constantly with a wooden spoon. It will form clumps and start to melt into an amber liquid - watch carefully, ensuring it doesn’t catch/burn.

When it is melted and golden-brown, add the butter and whisk until combined (this may take a couple of minutes). Be careful as the caramel will bubble and steam vigorously.

Drizzle in the cream slowly, again whisking constantly until fully combined (1-2 minutes). Remove from the heat.

Stir in the vanilla and salt to taste. Leave to cool.