Knead the wheat flour, baking powder, sugar, vanilla sugar, egg and butter into a short crust. Put in a cool place. Divide the dough into 2 equal pieces and roll out into 2 equal rectangles (approx. 32 x 22 cm). Place a plate on the baking sheet.
For the filling, the grated almonds and sugar are mixed with enough orange juice to make a spreadable mixture. So that the sheet of dough is evenly spread on the baking sheet (leaving about 1 cm free at the edge), place the other half of the dough on top and press the edges together well.
Prick several times with a fork. Bake everything at 175 - 195 ° C (top / bottom heat) for about 20 - 25 minutes. Prepare the icing with powdered sugar and 1 tablespoon orange juice and brush the pastry sheet immediately after baking. After cooling, cut the pastry into small squares.