Mix the flour, sugar and salt. Dice the butter. Rub the butter in the flour until the mixture resembles fine breadcrumbs.
Add the egg and just enough cold water until the dough is just moist enough to stick together. Gather the dough together and gently press it into a disc.
Wrap in plastic and place in the refrigerator for 20 to 30 minutes to firm up before rolling out.
On a floured surface, roll out ⅔ of the pastry and line bottom and sides of the greased tart or pie pan. Roll your rolling pin over top of pan to get rid of excess pastry.
Cover and refrigerate for 20 minutes to chill the butter.
Preheat the oven to 180°C.
Filling
Peel, core and dice the apples. Mix the apples with the raisins, sugar, cinnamon and custard powder.
Pile the filling in the pastry case, creating a slight dome in the centre.
Roll out the remaining dough into a circle large enough to cover the apple filling. Press down to seal the rim.
Egg wash the top and poke a few holes in the top to allow the steam to escape.
Bake for 25 to 30 minutes or until the pastry is golden and cooked.
Leave to cool for 10 min in the tin on a wire rack before serving.
Stuff to know
This quantity will feed 6 people and makes a tart with a 21 cm Ø. It is easier to crumble the butter into the flour when it is cold. Resting and refrigerating the dough makes rolling it out easier. It is less sticky. Enrich the filling with some nuts or mixed peel. Spread some frangipane on the bottom before adding the apple filling. Cut the top pastry into strips to make a lattice top. The small amount of custard powder will absorb the liquid from the apples.
Recipe by Jeroen Valkenier Recipes at https://jpvalkenier.com/apple-tart/