Peel apples, cut into quarters and remove cores. Cut into thick slices. Place in a medium pan with vanilla, cinnamon, star anise, lemon zest and 1/2 cup sugar. Add 1/4 cup water, cover with a lid and cook over low heat for 20 minutes until soft (add a little water if apples look too dry). Set aside to cool. Remove and discard vanilla pod, cinnamon and star anise.

Sift flours with two tablespoons castor sugar and a pinch of salt. Rub butter into flour until it forms crumbs. Beat egg yolk with two tablespoons cold water and add to the mixture. Knead gently until it forms a dough. Wrap in cling wrap and rest in fridge for 20 minutes.

Preheat oven to 200C. Grease base and sides of a deep, 23-centimetre pie dish. Cut pastry into two pieces, one slightly larger than the other. Roll out the larger piece to about 26 centimetres and line the bottom and sides of the dish. Place cooled apple filling in the pie. Roll out remaining pastry and put over filling. Press edges together to seal. Trim around the edge with the back of a knife to neaten. Use a fork to press indentations into the pastry edge. Make a vent in the middle of the pie with a sharp knife. Sprinkle over golden castor sugar. Bake for 35 minutes. Serve warm with vanilla ice-cream or cream.