Ferrero Rocher éclairs

Preheat the oven to 200ºC/180°C fan/gas mark 6 and line two large baking trays with greaseproof paper. Draw 12 roughly 10cm long lines on the paper to use as guidelines

For the choux pastry, combine the water, butter and salt in a saucepan. Gently melt the butter over a low heat without bringing the mixture to the boil (you want the butter to be just melted, and avoid evaporating too much of the water)

Once the butter has melted, bring the mixture up to the boil and tip all the flour into the pan in one go. Remove the pastry from the heat

Use a wooden spoon to beat the mixture as fast as you can, bringing it all together into a dough that pulls away from the sides of the pan

Once the dough starts to pull away, return the choux pastry to the heat and continue cooking and stirring the dough (no need to beat it as frantically at this stage) until an instant read thermometer reads 74°C. A little above this temp is fine as well. If you don’t have a thermometer, continue cooking the dough until the base of the saucepan is covered in a fine film of pastry

Remove the dough from the pan and transfer it to the bowl of a stand mixer with a paddle attachment (or another bowl if using a wooden spoon) to cool a little. It helps to spread the dough out at this stage to cool it faster

Once the dough reaches 63°C or cooler, it’s time to add the eggs. Lightly beat the eggs together in a jug

Mix the dough on low speed, and gradually beat the eggs into the dough, ensuring each addition is fully incorporated before adding the next. It’s unlikely that you will need all of the egg. Keep adding egg until you have a mixture that reluctantly drops from the paddle, leaving a V shape. Another way to test if the dough is ready is by scooping some up onto a spoon then counting slowly to 6 - it should have dropped by the time you reach 6 (slow) seconds

Dab a few dots of the mixture in each corner of the baking trays to stick the greaseproof paper to the surface of the baking trays

Fit a piping bag with a star nozzle that’s around 1.25cm wide (with a lot of teeth, if possible). Fill the piping bag with the choux pastry

Place the filled piping bag onto a flat surface and carefully flatten the pastry mixture inside, taking care not to squeeze it out of the bag. Using a pastry scraper or other thin, flat object, gently push the choux pastry down into the bag to remove air bubbles and collect all the dough in one place. Twist the bag at the top and pipe a little of the mixture to remove any air bubbles near the tip

Carefully pipe the pastry over the guidelines on the baking paper at a 45 degree angle, if possible. Try to achieve a very slight ‘dog bone’ shape with the pastry, as this will ensure they are more evenly shaped once baked. It’s also important to try to pipe fairly slowly, otherwise the éclairs will be too skinny

Sprinkle a few drops of water around the éclairs (not touching the pastry) and transfer to the oven to bake for 25 minutes. After 25 minutes, swap the trays around for a further 5 minutes, or until the pastry is deep golden brown and crisp – they should sound hollow when tapped

Prick the underside of the éclair shells with a cocktail stick and transfer onto a wire rack to cool completely

To make the Nutella mousse, whip the cream in a stand mixer with a whisk attachment (or an electric whisk) until soft peaks form, then carefully scrape out into a bowl

In the bowl of the mixer, whisk together the icing sugar, vanilla bean paste, cream cheese, Nutella and a pinch of salt then beat on medium high until pale and creamy

Fold in the whipped cream with a rubber spatula until combined

Transfer the Nutella mousse to a piping bag fitted with a fine nozzle and twist the end to seal

Make two holes in the end of the choux pastry cases. Snip off the end of the bag and pipe the mousse into either end of the éclairs, until full

To make the chocolate topping, melt the milk chocolate in a bain-marie and then allow to cool slightly

Dip the pastry cases into the melted chocolate and allow to set for a few minutes before topping with the chopped hazelnuts