- 55g butter, plus extra for greasing
- 70g plain flour, sifted
- 2 medium eggs
- 250g caster sugar
- Edible silver leaf, to decorate (from squires-shop.com, optional)
For the pastry cream filling
- 300ml full-fat milk
- 25g plain chocolate (70% cocoa solids), chopped
- 2 large egg yolks
- 55g caster sugar
- 30g plain flour
- Icing sugar, for dusting
- Preheat the oven to 180°C/ fan160°C/gas 4. For the choux pastry, put the butter and 150ml water in a large pan over a medium heat. When the butter has melted and the water is simmering, quickly add the flour and mix to a thick paste. Mix over the heat for 1 minute, then set aside to cool to room temperature.
- Add the eggs, 1 at a time, beating well before adding the second egg. You should get a thick, glossy, dropping-consistency mixture. Transfer to a piping bag fitted with a plain 1.5cm nozzle. Sprinkle 2 large baking sheets with a little water, then pipe on 25 golf-ball-size blobs, spaced apart. Bake for 15 minutes or until well risen and golden.
- Carefully make a hole in the base of each bun with a sharp knife. Pop back in the turned off oven for 5 minutes to crisp up the centres. Transfer to a wire rack to cool.
- Meanwhile, make the filling. Put the milk and chocolate in a pan over a medium heat, stirring to melt. When just simmering, remove from the heat. In a heatproof bowl, whisk the egg yolks and sugar together, until pale and creamy, then mix in the flour. Slowly mix in the chocolate mixture, then pour it all back into the pan. Return to a medium-low heat and cook, stirring continuously, for 5 minutes, until thick and glossy. Cool, dust the surface with a little icing sugar to prevent a skin forming.
- Spoon the pastry cream into a piping bag fitted with a plain 5mm nozzle. Fill each bun, pushing the nozzle through the base-hole.
- For the caramel, put the sugar and 2 tablespoons cold water in a wide, stainless-steel pan over a low heat. Melt gently, stirring, to dissolve the sugar. Increase the temperature and simmer, without stirring, until a golden amber colour – be careful as it will easily burn. Cool slightly.
- Carefully dip a little of each bun into the caramel, allow the excess to drip off and stack the buns up into a pyramid shape. Leave to firm up.
- To make the spun sugar, return the caramel to the heat to melt again. Dip in a fork and flick back-and-forth over the croquembouche, repeating until you have lots of fine strands of hardened caramel all over the buns. Decorate with flecks of silver leaf, if you like, to serve.