2 cups plain flour, plus extra for dusting
1 tsp baking powder
¼ cup caster sugar
175g unsalted butter, chilled, chopped
1 tsp vanilla extract
1 egg yolk
⅓ cup chilled water
2½ cups milk, extra for brushing
1 lemon, coarsely zested
5 egg yolks
⅔ cup caster sugar
⅓ cup plain flour
⅓ cup pine nuts
Icing sugar, for dusting
Double cream, to serve (optional)
Heat milk and zest in a saucepan until simmering. Remove from the heat and allow to infuse for 5 minutes. Put egg yolks, egg, sugar and flour in the large bowl of an electric mixer and beat until pale and increased in volume.
Slowly pour in hot milk, continuing to beat on low until combined. Rest a sieve over a large saucepan and pour through mixture to remove zest. Stir constantly over a low heat for 6-8 minutes or until custard thickens. If any lumps appear, stir with a whisk.
Transfer custard to a heatproof bowl and allow to cool slightly. Cover surface directly with plastic wrap. Refrigerate until chilled (about 3 hours). Custard can be prepared up to two days in advance.
To make pastry; put flour, baking powder, sugar, butter and vanilla in a food processor. Process until mixture resembles breadcrumbs. Add egg yolk and water, then process until mixture begins to form clumps.
Turn out onto a lightly floured surface. Knead until just smooth. On a floured surface, roll out three-quarters of the pastry to form a 34cm circle. Line a 23.5cm x 3cm flan tin (with removeable base) with pastry lid. Trim edges. Press pastry into fluted sides of tin so it extends above rim.
Preheat oven to 170°C. Gather pastry scraps and knead with remaining pastry until just combined. Roll out until large enough to cover top of pie. Brush pastry edge with water. Spread cold custard in pastry case and cover pie with pastry. Trim around edge. Pinch edges together until sealed.
Pierce the top of pie lightly with the tip of a knife. Brush with extra milk and sprinkle with pine nuts. Refrigerate for 15 minutes. Bake for 40-45 minutes or until golden. Let cool on a wire rack for 45 minutes, then remove from tin to cool completely. Dust with icing sugar and serve with double cream, if desired.