These delicious pastries are impressive enough to be found in a Parisienne bakery, and are so good served with a cup of strong coffee.
First, crystallise the flowers. Using a fork, beat the egg white until frothy. Use the cake-decorating paintbrush to paint the flowers with the egg white. Sprinkle with caster sugar and leave on kitchen paper for 2–3 hours, or until dry.
Make the craquelin. Mix the butter, sugar and flour in a small bowl to make a slightly soft, sticky paste. Roll into a ball, then place between 2 sheets of cling film. Roll out to about 3mm thick, then place flat in the freezer.
Make the orange crème diplomat. Heat the milk and vanilla bean paste together in a medium pan over a medium heat to just below boiling point.
Meanwhile, place the egg yolks and caster sugar in a medium bowl and hand whisk until light and fluffy. Add the cornflour and mix until just combined.
When the milk mixture is bubbling, pour about one third into the egg yolk mixture and whisk until smooth, then whisk in the remaining milk. Pour it all back into the pan and stir over a medium heat until the mixture is very thick.
Add the orange liqueur and orange spice drops to taste, then spoon into a shallow metal tray, cover with cling film and leave to cool in the fridge. Heat the oven to 220°C/200°C fan/425°F/Gas 7.
Start the choux. Heat the butter in a small pan with 180ml of water over a medium heat. When the butter has melted and the mixture is starting to bubble, remove it from the heat and add both flours. Stir with a wooden spoon to a smooth ball that pulls away from the sides very easily. Leave to cool for 5 minutes.
Meanwhile, cut out 12 craquelin circles of 2cm diameter and 12 circles of 3.5cm diameter. Place the circles on a lined baking sheet and return them to the freezer.
Gradually add the eggs to the choux dough, beating well after each addition, until it is smooth and shiny and thick enough to hold its shape when piped. Place the mixture into the large piping bag with the 1.5cm nozzle.
On the second lined baking sheet, pipe out 12 choux rounds of about 3cm diameter and 12 larger rounds of 5cm diameter. Top these with the craquelin circles from the freezer.
Place in the oven, immediately lowering the temperature to 200°C/180°C fan/400°F/Gas 6. Bake for 25 minutes, then turn off the oven and remove the buns. Pierce the base of each bun with a skewer to release the steam and return to the oven for 5 minutes to dry out a little. Remove from the oven and transfer to a wire rack to cool.
Make the icing. Mix together all the icing ingredients, except the colouring, to a thick, pouring consistency. Add colouring to give the desired shade. Cover with cling film.
Hand whisk the double cream for the crème diplomat until thickened, then add the cooled crème diplomat mixture and whisk until smooth. Spoon into the medium disposable piping bag and snip the end. Pipe the crème into each cooled bun through the hole in the base (you may need to make it a little bigger).
Top all the buns with a little orange icing, then stack one smaller bun on top of each larger bun, and finish with a crystallised flower. Refrigerate until serving the same day.