4 large Bramley apples (about 1.2kg/2lb 10oz), peeled, cored and cut into small chunks
275g/10oz fresh blackberries
50²µ/1¾´Ç³ú rolled oats
225g/8oz plain flour, plus extra for dusting
175g/6oz plain flour
30g/1oz caster sugar
150²µ/5½´Ç³ú caster sugar
100²µ/3½´Ç³ú demerara sugar
50²µ/1¾´Ç³ú hazelnuts, roasted and chopped
125g/4½oz chilled butter, cut into cubes
100²µ/3½´Ç³ú butter, at room temperature, cut into cubes
custard or double cream, to serve
1 large free-range egg, beaten