陆 lemon, juice only
2 lemons, zest only
12-15 large ripe plums, stones removed, chopped
100驳/3陆辞锄 rolled porridge oats
175g/6oz plain flour, sifted
160驳/5陆辞锄 caster sugar
50g/2oz caster sugar
50g/2oz dark muscovado sugar
butter, for greasing
100驳/3陆辞锄 butter, chilled, cut into cubes
custard, to serve