For the dough: flour and baking powder, mix well, add egg, the butter and vanilla. Knead dough until smooth, if you add 1-2 tbsp water. Allow the dough for 15 minutes in the refrigerator. Then roll out the dough and put it in the tray. It is best to put baking paper. Try to remain a little surplus for forming the grid. For the filling: grated apple and mix with remaining ingredients. Also very well happen if caramelize some sugar and put it in the stuffing. Cut remaining dough into strips 2 cm make a grid. Optional can coat them with one yolk becomes a golden crust. Bake in a moderate oven until ready.