Apple shortcake with passionfruit icing

Sift self-raising flour, plain flour, custard powder and sugar into a large bowl. Rub butter into flour mixture until mixture resembles fine breadcrumbs. Make a well in centre. Combine egg and 1/4 cup milk in a jug. Add egg mixture to flour mixture. Stir until a soft dough forms. Place on a floured surface. Knead for 30 seconds or until just smooth. Shape dough into a disc. Cover. Refrigerate for 30 minutes or until firm.

Preheat oven to 200°C/180°C fan-forced. Grease a 3cm-deep, 20cm x 30cm lamington pan. Line with baking paper, allowing a 2cm overhang at long ends.

Roll two-thirds of pastry out between 2 sheets baking paper into a 24cm x 34cm rectangle. Line base and sides of prepared pan with pastry. Spoon apple into pastry case. Roll out remaining pastry between baking paper to a 20cm x 30cm rectangle. Place over apples. Press edges to seal. Brush top with remaining milk. Bake for 40 minutes or until golden. Cool for 15 minutes. Remove from pan.

Meanwhile, make icing Sift sugar into a bowl. Stir in butter and passionfruit pulp until smooth and thick. Spread over cake. Set aside for 20 minutes to set. Serve.