500g/1lb 2oz blackberries, frozen or fresh
1 lemon, juice and zest only
240g/9oz plain flour, plus extra for flouring
50驳/1戮辞锄 caster sugar
陆聽tsp ground cinnamon
1 tbsp cornflour
60g/2录 oz ground almonds
140g/5oz cold butter, diced
1 free-range egg yolk, beaten
good-quality vanilla ice cream