This tower of éclairs will test your mettle even if you fancy yourself as next year's Bake Off winner.
For this recipe you will need 3 baking sheets, 6 disposable piping bags, a 12mm/½in plain nozzle, wire racks, 2 long thin nozzles, a star nozzle, a sugar thermometer and a large empty water bottle.
For the pâte sucrée, stir the flour and ground almonds together in a large bowl. Add the butter and rub it in using your fingertips until the mixture resembles breadcrumbs. Stir in the sugar. Break in the egg and work into the mixture using your fingers, bringing it together to form a soft dough.
Tip the dough onto a lightly floured work surface and shape it into a ball. Flatten into a disc and wrap in cling film. Chill for at least 3 hours.
For the choux pastry, preheat the oven to 220C/200C Fan/Gas 7. Line 3 baking sheets with baking parchment. On the first sheet draw 16 x 12cm/4½in lines, spaced well apart. On the second sheet, draw 14 x 9cm/3½in lines spaced well apart. On the third sheet draw 12 x 6cm/2½in lines and 2 circles with diameters of 3cm/1¼in and 4cm/1½in again spaced well apart. Turn the paper over so the pencil marks are underneath but can be seen, to use as a template.
Put the butter, salt and 500ml/18fl oz water into a large saucepan. Heat gently until the butter has melted, then bring to the boil. (Don’t let the liquid boil for any length of time, or you will drive off too much moisture.) Immediately remove from the heat and tip the flour into the pan. Beat with a wooden spoon to form a smooth ball of dough that leaves the sides of the pan clean.
Now vigorously beat the egg into the hot dough, a little at a time. This takes some elbow grease! As you add the egg, the dough will become stiff and glossy. Stop adding the egg if the dough starts to become loose (though you should use up all or most of it).
Spoon the mixture into a piping bag fitted with a 12mm/½in plain nozzle. Pipe the mixture onto the templates on the baking sheets, filling the circles with dough.
Bake for 10 minutes, then reduce the oven temperature to 190C/170C Fan/Gas 5 and bake for a further 25-30 minutes until dark golden-brown. When baked, the pastry should be crisp and dry. As soon as you remove it from the oven, transfer to a cooling rack and pierce each piece of choux gently with a skewer (this allows steam to escape and stops the pastry becoming soggy). Put the choux on wire racks to cool.
Roll the chilled pâte sucrée out on a lightly floured surface to 5mm thick. Using plates or cake tins as templates, cut out four circles which are 18cm/7in, 15cm/6in, 12cm/4½in and 8cm/3¼in in diameter. Place the pastry on 2 baking sheets. Cover the pastry with a sheet of baking parchment and place another baking tray on top. Bake for 12 minutes, remove the top baking sheets and baking parchment and bake for a further 10-15 minutes until the pastry is dark golden-brown and dry. Remove from the oven and leave to cool on the trays.
For the pistachio crème pâtissière, pour the milk into a pan, add the pistachio paste and bring to the boil, then remove from the heat.
Whisk the sugar, egg yolks and cornflour together in a large bowl. Pour a little of the hot milk onto the egg mixture, whisking continuously. Whisk in the rest of the hot milk until well combined, then return to the pan. Cook the mixture over a gentle heat, stirring continuously, until the mixture thickens.
Remove from the heat and pass the mixture through a sieve into a clean bowl. Beat in the butter until melted. Leave to cool, cover the surface with cling film to prevent a skin forming and chill. When cool, spoon into a piping bag fitted with a long thin nozzle.
For the raspberry crème pâtissière, pour the milk into a pan, add the raspberry powder and bring to the boil, then remove from the heat.
Whisk the sugar, egg yolks and cornflour together in a large bowl. Pour a little of the hot milk onto the egg mixture, whisking continuously. Whisk in the rest of the hot milk until well combined, then return to the pan. Cook the mixture over a gentle heat, stirring continuously, until the mixture thickens.
Remove from the heat and pass the mixture through a sieve into a clean bowl. Beat in the butter until melted. Leave to cool, cover the surface with cling film and chill before using. When cool, spoon into a piping bag fitted with a long thin nozzle.
Make a small hole in each piece of choux. Fill half of each size éclair with the pistachio crème pâtissière and the remaining half with raspberry crème pâtissière. Fill the large choux bun with pistachio crème pâtissière and the smaller choux bun with the raspberry crème pâtissière.
For the icing, add enough water to the fondant icing sugar to make a very stiff icing. Divide the mixture into 2 bowls. Add the raspberry liqueur to one bowl and a tiny amount of pink food colouring paste to make a pale pink icing. Add the almond extract to the other bowl and a tiny amount of green food colouring paste to make a pale green icing.
Spoon the icing into 2 separate disposable piping bags and snip off the ends. Pipe the pink icing onto the raspberry filled éclairs and choux bun and the green icing onto the pistachio filled éclairs and choux bun. Smooth with a palette knife. It doesn’t matter if the icing drips down the sides a bit as this will be covered by the buttercream decoration.
For the buttercream, place the butter in the bowl of a freestanding mixer and beat until softened. Add the icing sugar and milk and beat gently to begin with then increase the speed and beat on high for 3 minutes, or until white and fluffy. Spoon the buttercream into a piping bag fitted with a star nozzle.
For the caramel, tip the sugar into a pan with 100ml/3½fl oz water and the glucose syrup. Bring to the boil and continue cooking until the mixture reaches 170C on a sugar thermometer. Remove from the heat and plunge the base of the saucepan into a sink of cold water to stop the cooking process. (CAUTION: melted sugar is very hot. Take care not to burn yourself.)
To assemble, put the largest pastry disc on a serving plate. Put a large, empty plastic water bottle in the middle (this will help support the éclairs during the assembly). Dip the end of a green, 12cm/4½in éclair in the hot caramel and quickly and gently press onto the pastry disc (leaning it against the bottle to help it stand on end). Using a palette knife spread some caramel up one side of the éclair, Dip the end of a pink, 12cm/4½in éclair in the hot caramel and quickly and gently press onto the pastry base and the side of the green éclair. Repeat this process, using all the 12cm/4½in éclairs around the base, alternating in colour.
Let the caramel set, then trim the tops off the éclairs so they form a level base for the 15cm/6in pastry disc. Remove the bottle. Cover the underside outside edge of pastry disc with hot caramel and place on top of the éclairs. (If your caramel starts to harden heat it very gently until soft.)
Repeat the next layer using the 9cm/3½in éclairs, alternating in colour.
Repeat as above with the12cm/4½in pastry disc and the 6cm/2½in éclairs, alternating in colour.
Finally stick the 8cm/3¼in pastry disc on top followed by the green choux bun, topped with the pink choux bun.
To decorate, pipe the buttercream around the edge of each pastry disc and between the gaps of each éclair.
