Fold along the diagonal and press the edges with a fork. Arrange them in a wide tray.
Bake at 392°F (200 °C) in a preheated oven for 15 min. Separately boil a syrup from the water and sugar ahead of time, leave it to cool.
Pour it over the Triangular Puff Pastries in the tray and leave for 3-4 hours to soak in the syrup, then eat with joy. Bon appetit!