Mix together the beaten eggs with the sugar, the flour sifted with the baking powder and ground walnuts.
Roll out the sheets and cut them into strips 2″ (5 cm) wide. Arrange the strips on top of one another, put a little filling at the end of each and fold them up into triangles.
Arrange the triangular phyllo pastries in a buttered tray and pour the melted butter over them.
Bake in a preheated moderate oven until they turn the color of light caramel.
For the syrup:
Pour the hot syrup over the cold triangular phyllo pastries and leave them to soak it in for 24 hours.