Grease a 26cm loose-bottomed tart pan.

Beat butter and 1 cup caster sugar in the bowl of an electric mixer for 2-3 minutes until thick and pale. Add 1 tsp vanilla, then 4 egg yolks, one at a time, beating well after each addition. Add 1 tbsp iced water. Using a metal spoon, fold in the flour.

Using your hands, bring dough together and cut into a on-third and a two-third portion. Roll out the larger portion of dough on a lightly floured surface (I prefer between two pieces of grease proof) then line the base and sides of the pan. This pastry can be a little difficult to work with especially on a warm day so just push it into position.

Roll out the remaining third of the dough between lightly floured grease proof paper large enough to cover the pan. Refrigerate pastry case and lid.

Combining apples in a saucepan with the cinnamon, remaining ½c sugar and 1 tsp vanilla, and ¼c water. Cook over low heat until apple starts to soften. Cover and cook, stirring occasionally, for 12-15 minutes until very soft. Drain in a colander, discarding liquid and cinnamon (it's essential that the filling be quite dry, or the pastry will be soggy). Set apple aside to cool completely.

Preheat the oven to 180°c. Fill the pastry case with apple and brush the edges of the pastry with a little water. Using the baking paper as a guide, slide the pastry lid over the filling. Trim the edges and crimp to seal. Run the tines of a fork over the pastry in a decorative pattern. Lightly whisk the remaining egg yolk and brush the top of the pastry. Bake for 45-50 minutes or until golden.