For the Choux buns
- Preheat the oven to 200 C / fan 180 C / Gas mark 4. Line 3 baking sheets with baking parchment. Pour the water into a large saucepan and add the butter. Cover the top of the saucepan with cling film and bring to the boil. Remove the cling film (take care to avoid the steam) and add all the flour quickly in one go.
- Remove the pan from the heat and beat the mixture vigorously to a firm paste, stirring continuously. Transfer the mix to a bowl and leave to cool for 5 minutes.
- Beat in the eggs a little at a time (either by hand or in a food mixer), stirring vigorously until the paste is smooth and glossy. Continue adding the the eggs until you have a smooth ribbon consistency.
- Spoon the mixture into a large piping bag fitted with a plain nozzle about 5mm dia. Pipe around 75 rounds (25 per tray), each about the diameter of the top section of the anodised top-cone, onto the baking sheets. Leave enough space between each round to allow for spreading. Dip a finger in cold water and flatten any peaks.
- Bake for 20 minutes until risen and golden, rotating the baking sheets half way through cooking. Remove from the oven and pierce the base of each bun with the tip of a knife or skewer to allow steam to escape.
- Return to the oven and cook for a further 3 minutes to dry out. Remove from the oven and leave to cool on wire racks.
For the filling
(As an alternative, you can fill the buns with crème Chantilly).
- Pour the milk into a pan with the vanilla bean paste. Bring the milk slowly to a simmer over a low heat. In a separate bowl, whisk the egg yolks, sugar and flour until pale and creamy.
- Pour the warm milk over the egg mixture, stirring. Pour the mixture back into the pan and cook over a low heat for 4-5 minutes, whisking, until the mixture starts to thicken and the whisk leaves a trail in the custard. The mixture should be thick and the flour taste cooked out.
- Remove from the heat and pass through a fine sieve into a bowl. Cover the surface with cling film to prevent a skin forming and leave to cool. Chill until ready to use. Spoon the chilled custard into a piping bag fitted with a long nozzle (like the nozzles used to pipe jam into doughnuts) and fill the choux buns through the steam holes.
- The choux buns can be made in advance and frozen, or can be stored unfilled for up to 3 days in an airtight container. If the buns are soft after defrosting or storage, lay them on lined baking sheets and bake at 180 C / fan 160 C / mark 4 for 5 minutes until crisp.
To build the Croquembouche
- To assemble the croquembouche, start by making the caramel which will act as the glue to hold the whole thing together. Use 300g of caster sugar and 225ml of water, (this will be more than enough, but you will find the temperature is easier to control than with a smaller amount). You will also need a jam thermometer.
- Beware : Melted sugar is VERY hot and sticky - handle with care. Place sugar and water in a clean pan and dissolve by stirring gently on a low heat.
- Once dissolved, raise the temperature to boiling
- Whilst boiling do not stir. Keep the sides of the pan and the thermometer continuously washed down with a little water to re-dissolve any sugar crystal which may form. Boil as rapidly as possible to the required temperature 154 C.
- If any scum appears on the surface remove it with a spoon.
- When the required temperature has been reached, remove the pan quickly from the heat and plunge it into a pan of cold water for a few seconds to prevent the temperature rising further due to heat absorbed by the saucepan.
- Holding each choux bun on its side, dip into the caramel (which will be very HOT) and arrange the buns around the baser of the mould. The caramel will help them stick together. Continue dipping the buns in the caramel and layering them up around the mould, until you reach the top. If the caramel gets too thick, briefly return it to the heat to warm through, but be careful not to burn it. Once assembled, leave the caramel to set for at least 30 minutes
You can serve the croquembouche on the mould or very carefully lift the finished article off the mould. You will need to loosen any hardened caramel from the base and then it will slip off the mould. Place on a flat serving plate.
Decorating your Croquembouche
Your croquembouche will look best if decorated with spun sugar. There are various methods for making spun sugar. Here are two to choose from :
Method 1 (fun, but can be messy!). Prepare your workspace by placing two sticks (wooden spoons are ideal) to project beyond the edge of the work surface and laying plenty of sheets of paper underneath on the floor. Prepare caramel as before (you will probably have enough left). Dip a fork into the sugar and using a backhand flick., throw off the sugar picked up by the prongs, so that threads are formed across the two sticks. Repeat until you have enough strands to drape around the croquembouches. Serve as soon as possible.
Method 2. Use the same caramel as above. Dip the back of a wooden spoon into the caramel and using the back of another wooden spoon pat the 2 spoons together and start working the ribbon of caramel backwards and forwards between the spoons, until it becomes pliable and stretches into fine strands. Using the wooden spoons to stretch the caramel, twist the caramel around the croquembouche. This will take some practice but there is enough caramel to make more than you need so persevere - practice makes perfect.
Remember Croquembouche is best eaten on the day it is made, as once the choux buns are filled, they start to soften and the spun sugar will draw moisture out of the air and lose its crunch. If you are planning a centrepiece for a special occasion, try to find time for a test run before the main event.