How to make
Thaw the puff pastry, roll it out slightly and cut into 8 identical squares. Mix the ground hazelnuts, soft butter, brown sugar and breadcrumbs in a bowl. Put 1 tsp of the filling in each square.
Fold along the diagonal and press the edges with a fork. Arrange them in a wide tray.
Bake at 390°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!
