Using a mixer combine flour and butter then add all the other ingredients until you have a crumbly dough. Wrap it in cling film and let it rest in fridge for at least 1 hour.
Pre heat oven at 360°F.Mix apples with cinnamon, sugar and vanilla.In a glass mix cornstarch and lemon,Melt butter in a pan, stir in apple, let them bronwn, add the lemon/ cornstarch mixture and cook 5 more minutes.
Divide the dough in two parts, roll out one and line a round pan. Cover the dough with oven parchment, add a weight ( with dry beans or similars) and bake for 15- 20 minutes.
Remove parchment and beans, put in the baked dough the filling, cover it with the other half dough, rolled out and with a hole in the centre to let the humidity escape.Brush with milk, sprinkle with cane sugar and bake for about 45 minutes.Serve with a good quality custard ice cream.