1 ¾ cups plain flour
¼ cup custard powder
1/3 cup icing sugar mixture
175g cold unsalted butter, chopped
1 egg yolk
Extra Icing sugar mixture, to decorate
Frozen custard, to serve
1.25kg Granny Smith apples
½ cup caster sugar
1 tablespoon cornflour
¾ cup frozen raspberries
¼ cup raspberry conserve
Invert base of a 20.5cm round springform pan (base measures 19.5cm). Grease and line base with baking paper.
To make pastry, process flour, powder, sugar and butter in a food processor until mixture resembles fine crumbs. With motor operating, add yolk and 2 tablespoons cold water until mixture comes together. Remove.
Wrap one third of the pastry in plastic wrap. Freeze. Shape remaining pastry into a flat disc. Refrigerate, covered, for 20 minutes.
To make filling, peel and core apples. Cut into 2cm thick slices. Place in a stockpot with sugar and 1 tablespoon water. Stir over heat until sugar is dissolved. Bring to boil. Cover with lid. Gently boil, stirring occasionally for about 8 to 10 minutes, or until just tender.
Blend cornflour with 1 tablespoon water in a small jug. Stir into apples with raspberries and conserve. Bring to boil, stirring until thickened. Transfer to a large bowl. Refrigerate, covered, until cold.
Roll out pastry disc between two sheets of baking paper until large enough to line base and side of prepared pan. Lift into pan. Trim edge. Refrigerate for 15 minutes. Cover with baking paper. Fill with dried beans or rice.
Cook in a moderately hot oven (190C) for 10 minutes. Remove paper and beans. Cook for a further 10 minutes, or until pastry is dry. Remove from oven. Cool slightly.
Spoon filling into pastry case. Coarsely grate frozen pastry over top. Return to oven.
Cook for a further 20 minutes, or until golden brown. Stand in pan for 15 minutes.
Remove pie from pan. Lightly dust with sifted extra icing sugar. Using a serrated knife, cut into wedges. Serve with frozen custard.
TIP! Use kitchen scales to correctly divide pastry. You will need around 9 small Granny Smith apples for this recipe.