400g soft brown sugar
400g unsalted butter
500g plain flour
icing sugar, to dust
Preheat the oven to 180°C/gas mark 4. Core and thickly slice the apples and place in a saucepan with the juice of the lemon, 200ml cold water and 100g sugar. Simmer for 12 mins, stirring occasionally, until the apples are just soft. Drain and set the pan aside.
Using the fingertips, rub the butter into the remaining sugar and flour in a large bowl. Press two-thirds of it into a greased and lined 23 x 30cm deep tray, then stir the remainder into the apple mixture roughly and pour on top. Mix in the custard in swirls and bake in the preheated oven for 30 mins. Remove and leave to cool in the tray. Once cool, dust the tray bake with icing sugar, cut into 15 squares and serve.
Other tray bake recipes in our Sept/Oct 2016 issue: