Blackberry crumble cake with pistachio custard recipe
 This showstopping cake takes traditional British blackberries and crumble and serves them with a vivid pistachio custard. 230g/8oz unsalted butter, plus extra for greasing20ml/¾fl oz neutral oil (such as vegetable or sunflower)220g/7¾oz golden caster sugar4 free-range eggspinch sea salt1 tsp vanilla bean paste200g/7oz self-raising flour½ tsp baking powder30g/1oz ground almonds300g/10½oz blackberries, chopped30g/1oz pistachios, chopped30g/1oz plain flour40g/1½oz demerara sugar20ml/¾fl oz double cream 230g/8oz unsalted butter, plus extra for greasing 20ml/¾fl oz neutral oil (such as vegetable or sunflower) 220g/7¾oz golden caster sugar 4 free-range eggs pinch sea salt 1 tsp vanilla bean paste 200g/7oz self-raising flour ½ tsp baking powder 30g/1oz ground almonds 300g/10½oz blackberries, chopped 30g/1oz pistachios, chopped 30g/1oz plain flour 40g/1½oz demerara sugar 20ml/¾fl oz double cream 250ml/9fl oz full-fat milk250ml/9fl oz double cream1 tsp vanilla bean paste pinch sea salt100g/3½oz caster sugar5 free-range egg yolks 20g/¾oz pistachio paste 250ml/9fl oz full-fat milk 250ml/9fl oz double cream 1 tsp vanilla bean paste pinch sea salt 100g/3½oz caster sugar 5 free-range egg yolks 20g/¾oz pistachio paste Method To make the cake, preheat the oven to 180C/160C Fan/Gas 4. Grease a 24x24cm/9.5x9.5in square tin with butter and line with baking paper. Put the butter, oil and golden caster sugar in a stand mixer or in a bowl. Cream together using the paddle attachment or a hand-held electric whisk until pale and fluffy. Beat in the eggs one at a time, followed by the salt and vanilla. Fold in the flour, baking powder and almonds. Pour the cake mixture into the tin and top with the chopped fruit. Mix together the pistachios, flour and demerara sugar in a bowl. Use your fingertips to breadcrumb the cream in to create little clusters of crumble – do not over-mix. Scatter all over the cake and fruit. Bake for about 45 minutes–1 hour, until a skewer inserted comes out clean. Leave the cake to cool before removing from the tin. To make the pistachio custard, stir together the milk, cream, vanilla, salt and half of the caster sugar in a saucepan and place over a medium heat. Meanwhile, in a separate heatproof bowl, whisk the egg yolks, pistachio paste and remaining sugar to combine. When the milk is steaming hot and just about to come to the boil, slowly and carefully pour two-thirds of the milk mixture over the yolks mixture. Whisk vigorously as you pour until the mixture is smooth and combined. Pour the yolk mixture back into the pan with the remaining milk, reduce to a low heat and whisk well to incorporate. Stir with a spatula constantly until it coats the back of a spoon. Remove from the heat and serve with slices of the cake. This cake will keep in the fridge in an airtight container for three days. To make the cake, preheat the oven to 180C/160C Fan/Gas 4. Grease a 24x24cm/9.5x9.5in square tin with butter and line with baking paper. To make the cake, preheat the oven to 180C/160C Fan/Gas 4. Grease a 24x24cm/9.5x9.5in square tin with butter and line with baking paper. Put the butter, oil and golden caster sugar in a stand mixer or in a bowl. Cream together using the paddle attachment or a hand-held electric whisk until pale and fluffy. Beat in the eggs one at a time, followed by the salt and vanilla. Fold in the flour, baking powder and almonds. Pour the cake mixture into the tin and top with the chopped fruit. Put the butter, oil and golden caster sugar in a stand mixer or in a bowl. Cream together using the paddle attachment or a hand-held electric whisk until pale and fluffy. Beat in the eggs one at a time, followed by the salt and vanilla. Fold in the flour, baking powder and almonds. Pour the cake mixture into the tin and top with the chopped fruit. Mix together the pistachios, flour and demerara sugar in a bowl. Use your fingertips to breadcrumb the cream in to create little clusters of crumble – do not over-mix. Scatter all over the cake and fruit. Bake for about 45 minutes–1 hour, until a skewer inserted comes out clean. Leave the cake to cool before removing from the tin. Mix together the pistachios, flour and demerara sugar in a bowl. Use your fingertips to breadcrumb the cream in to create little clusters of crumble – do not over-mix. Scatter all over the cake and fruit. Bake for about 45 minutes–1 hour, until a skewer inserted comes out clean. Leave the cake to cool before removing from the tin. To make the pistachio custard, stir together the milk, cream, vanilla, salt and half of the caster sugar in a saucepan and place over a medium heat. To make the pistachio custard, stir together the milk, cream, vanilla, salt and half of the caster sugar in a saucepan and place over a medium heat. Meanwhile, in a separate heatproof bowl, whisk the egg yolks, pistachio paste and remaining sugar to combine. When the milk is steaming hot and just about to come to the boil, slowly and carefully pour two-thirds of the milk mixture over the yolks mixture. Whisk vigorously as you pour until the mixture is smooth and combined. Meanwhile, in a separate heatproof bowl, whisk the egg yolks, pistachio paste and remaining sugar to combine. When the milk is steaming hot and just about to come to the boil, slowly and carefully pour two-thirds of the milk mixture over the yolks mixture. Whisk vigorously as you pour until the mixture is smooth and combined. Pour the yolk mixture back into the pan with the remaining milk, reduce to a low heat and whisk well to incorporate. Stir with a spatula constantly until it coats the back of a spoon. Remove from the heat and serve with slices of the cake. This cake will keep in the fridge in an airtight container for three days. Pour the yolk mixture back into the pan with the remaining milk, reduce to a low heat and whisk well to incorporate. Stir with a spatula constantly until it coats the back of a spoon. Remove from the heat and serve with slices of the cake. This cake will keep in the fridge in an airtight container for three days.