Preheat the oven to 180°C/160°C fan. Boil the water, milk, orange flower water, salt, sugar and butter in a large saucepan.
Once boiling, quickly add the flour and stir quickly and firmly until the dough is smooth and comes away from the sides of the pan.
Transfer to a mixing bowl (or electric mixer) and gradually add the eggs. Whisk until you have a lovely smooth, sticky paste. At this point, you can transfer the pastry to a piping bag and keep refrigerated for up to 5 days.
Using a piping bag, pipe out small heaps on baking trays covered in greaseproof/baking paper (or Silpat) Leave a good space between each mound, as they will spread out during baking.
Brush with a glaze of one egg yolk mixed with a tablespoon of water. Bake in the oven for 20-25 minutes without opening the oven door.
Orange Caramel Sauce
Put the sugar with 2 tablespoon water into a small saucepan and stir to dissolve as much as possible. Over a medium heat leave to cook without stirring until a golden syrupy caramel forms. This should take about 10 minutes.
Stir in the butter, still over the gentle heat and keep stirring for about 10 minutes until thickened. Don't worry if it looks like too much butter at this point: when you add the cream it will all come together.
Turn down the heat and add the warm cream, zest and liqueur gradually. It will look runny but that's good. Keep it bubbling away for another 5 minutes then cool.
Candied Fruit Ice Cream (prepare separately in advance)
Make one quantity of ice cream - recipe link in notes below.
Notes
Ice Cream Filling: see the separate recipe and instructions for no-churn Candied Fruit Ice Cream (Glace Plombières).Orange Caramel Sauce: As the caramel cools it will thicken. It can last up to 3 weeks if stored in a sealed jar in the fridge. Just reheat slightly in the microwave when ready to serve.