Put all the ingredients except the flour and eggs into a saucepan and bring to a boil.
Add all the flour at once and stir well with a spatula: within a minute the dough should cook through and pull away from the bottom and sides of the pan.
Remove from the heat and let cool for 15-20 minutes, or transfer straight to a stand mixer and cool on the lowest speed.
Once cooled, add the eggs to the dough in batches and mix until smooth - the finished dough drips from the whisk in a triangle shape.
Transfer the dough to a piping bag fitted with a tip and pipe the cookies onto a baking tray.
Bake for 15 minutes at 200°C, then another 15-20 minutes at 170-180°C until golden brown. Dust the finished cookies with powdered sugar.