Knead the dough (flour, water, salt and 60 g of butter) without overworking it and refrigerate at 5 °C for at least 2 hrs. Place the butter for the turns in the middle of the dough. Give two turns, leave to rest for at least 2 hrs. Repeat the process twice. The final two turns should be done just before the pastry is used.
Roll the dough out to a thickness of 2.5 mm and cut out irregular triangular shapes. Sprinkle both sides with icing sugar and cook in a panini maker between two sheets of baking parchment.
Pipe dots of light mascarpone cream onto 2 puff pastry triangles. Position one on top of the other, slightly off centre, and finish with a 3rd triangle. Add the soft dulce de leche and decorate with a caramelized pecan nut.