Giant Ferrero Rocher éclair to share

Method

1. Heat the oven to 200ºC fan/gas 7. Line a large baking sheet with baking paper. Sift the flour twice into a mixing bowl, then set beside the hob. Put the milk, butter, sugar, salt and 90ml water in a small saucepan over a low heat, stirring until the sugar dissolves and the butter melts (don’t let it bubble). Once the butter is fully melted, turn the heat up to high and bring to a rolling boil. As soon as the butter gathers in the middle of the pan, remove from the heat and add all the flour. Quickly stir the mixture to fully incorporate the flour, then return to a low heat and cook, stirring constantly, for 2 minutes.
2. Transfer the dough to a stand mixer fitted with the paddle attachment, then mix on low speed for 3-4 minutes until the dough is no longer hot but still warm to the touch. (Or beat with an electric hand mixer or with a wooden spoon and elbow grease.)
3. Add about half the beaten eggs, then increase the mixer speed to medium and beat until fully incorporated. Gradually add the remaining beaten eggs until the mixture is thick and shiny and drops off a spoon when tapped lightly on the side of the pan (you may not need all the egg). If it clings, beat in another lightly beaten egg, 1 tsp at a time, to get the right consistency.
4. Scoop the choux paste into a large piping bag, then snip the end so you have a hole about 4cm in diameter. Pipe a long sausage shape of choux onto the prepared tray, about 35cm long, then bake for 25 minutes. Turn the temperature down to 170°C fan/gas 5 and bake for 15-20 minutes more until well risen, golden and crisp. Set aside to cool (see Make Ahead).
5. When ready to assemble, whip the cream for the filling to soft peaks, then stir in the chopped Ferrero Rocher. Slice the éclair in half horizontally and fill the bottom half with the cream mixture, then put the top back on. Drizzle the melted chocolate over the top of the éclair, then sprinkle with toasted hazelnuts to serve.