Preheat oven to 180°C.
Firstly prepare the craquelin. Place the softened butter into a bowl and add the sugar and flour, combine to create a dough. Then roll out the dough thinly (1 mm thick) between 2 sheets of parchment paper. Keep in the freezer until required.
In a saucepan, combine the milk, sugar, and the diced. Bring the mixture to a boil, then remove from heat.
Add flour all at once and stir quickly with a spatula or wooden spoon until all the flour is fully incorporated. Remove the pan from the heat and pour the contents into a bowl, then add the eggs one by one mixing vigorously.
Spoon the choux pastry into a piping bag and pipe golf-ball size pieces on a baking sheet lined with parchment paper.
Cut out discs of craquelin to the size of the choux and place onto the choux.
Bake the choux for 30-40 minutes and leave to cool.
When the choux are cooled, fill the choux with the pastry cream and set aside.
Then, prepare the glazed, in a small bowl, combine the icing sugar , cocoa powder and stir with just enough of water to create a smooth and pourable glaze. Gently spoon the glaze over the choux and remove excess if needed.
Place on the serving dish and serve within a few hours. (although, it is best eaten straight away! )
Finally, combine the lemon curd and crème patissière in a bowl and fill the choux either using a piping bag fitted with a nozzle or by slicing the choux by half.