1) Grease 1 medium sized cake pan with butter.
2) Preheat oven to temperature of 250 degrees.
3) Mix the ingredients for the pastry to make a dough.
4) Divide into two portions, one bigger than the other.
5) Roll the bigger dough ball flat with a rolling pin.
6) Line the greased can pan with the pastry. Cut any extra that might hang out of the pan. prick
7) To make the filling, mix water and sugar. Boil to make syrup.
8) Add vanilla powder and mix well.
9) Add the apples and cook till all the juices go away. Stir constantly to make sure that the apples do not burn.
10) Put the smaller dough piece on parchment paper and roll flat. Cut into strips (to decorate the tart).
11) Put the cooked apples into the pastry lined pan, decorate with the flat pasrty strips cut from the smaller dough piece (criss-cross pattern).
12) Brush with the egg.
13) Bake in the preheated oven for 15-20 minutes.
14) Remove from the oven and let the tart cool to room temperature.
15) Cut into wedges and serve at room temperature, or even chilled.