Method

• 1.
  Preheat oven to 180°C. Grease a 20cm x 30cm x 5cm lamington pan and line base with baking paper. Dust sides with flour, shaking off excess
• 2.
  For the custard, place yolks, sugar and vanilla in a medium heatproof bowl and whisk over a saucepan of gently simmering water until pale and thickened. Gradually stir in warmed cream. Cook custard, stirring continuously, for 8-10 minutes until the custard is thick enough to coat the back of a spoon. Be careful not to scramble the eggs. Remove from heat. Soak gelatine leaf in cold water for 5 minutes to soften. Squeeze excess water from the gelatine, then stir into the custard until melted and combined. Transfer mixture to a new bowl over iced water, stirring frequently until cooled completely. Combine mascarpone and custard mixture in the bowl of a stand mixer with the whisk attachment and whisk on high speed until stiff peaks form. Transfer to a clean bowl and cover with plastic wrap. Refrigerate until needed.

• 3.
  Place eggs in the bowl of a stand mixer with the whisk attachment and whisk for 2 minutes. Gradually add 150g sugar and whisk for a further 5 minutes or until pale, then whisk in butter. Fold in sifted flours. Pour mixture into prepared pan, and tap on bench twice to remove large air pockets.
• 4.
  Bake for 30 minutes or until cooked and golden. Cool in pan for 10 minutes, then turn onto a wire rack to cool completely.
• 5.
  Place apples, remaining 1/2 cup (110g) sugar and vanilla in a saucepan. Cook, stirring regularly, for 10-12 minutes until apple is soft and a light caramel colour. Soak gelatine in cold water for 5 minutes to soften. Squeeze out excess water, then stir into apple mixture until melted and combined. Set aside to cool completely.
• 6.
  Place cake on a large platter. Spread over mascarpone custard, top with apple and dulce de leche, and serve immediately.