Rhubarb and custard crumble bars recipe
 Gorgeously crumbly, soft and sweet with a crunchy oat topping – perfect for afternoon tea or springtime bake sales. 250g/9oz soft unsalted butter, plus extra to grease300g/10½oz plain flour70g/2½oz dark brown sugar100g/3½oz caster sugar1 tsp ground cardamom60g/2¼oz rolled oats 1 egg yolk 250g/9oz soft unsalted butter, plus extra to grease 300g/10½oz plain flour 70g/2½oz dark brown sugar 100g/3½oz caster sugar 1 tsp ground cardamom 60g/2¼oz rolled oats 1 egg yolk 450g/1lb rhubarb (preferably forced), chopped into 3cm/1¼in batons 1 tbsp cornflour 25g/1oz caster sugar300ml/10fl oz ready-made chilled vanilla custard 25g/1oz flaked almonds 450g/1lb rhubarb (preferably forced), chopped into 3cm/1¼in batons 1 tbsp cornflour 25g/1oz caster sugar 300ml/10fl oz ready-made chilled vanilla custard 25g/1oz flaked almonds Method Preheat the oven to 180C/160C Fan/Gas 4. Grease and line a 31x21cm/12½–8¼in rectangular tin with baking paper.In a food processor, pulse the butter, flour, brown sugar, caster sugar and cardamom into fine breadcrumbs.Weigh out 200g/7oz of this mixture into a bowl for the crumble topping; stir in the oats and set aside.Add the egg yolk into the remaining mixture, then pulse in the processor until a dough is formed. Press this dough into the baking tin, ensuring it is spread evenly, then use a fork to prick the base all over.Bake for 15 minutes, then remove and let cool slightly as you prepare the rhubarb filling.To make the filling, combine the rhubarb in a bowl with the cornflour and caster sugar.Spread the vanilla custard over the slightly cooled and cooked biscuit base, then layer the rhubarb batons in tight rows. Sprinkle with the oat crumble topping.Bake for 40 minutes. Take the tray out of the oven and sprinkle the flaked almonds over the crumble topping. Return to the oven for an additional 10 minutes, or until the flakes are lightly toasted and the bake is golden in colour. Cool for 20 minutes before slicing into bars. Enjoy warm or chill and enjoy the next day. Preheat the oven to 180C/160C Fan/Gas 4. Grease and line a 31x21cm/12½–8¼in rectangular tin with baking paper. Preheat the oven to 180C/160C Fan/Gas 4. Grease and line a 31x21cm/12½–8¼in rectangular tin with baking paper. In a food processor, pulse the butter, flour, brown sugar, caster sugar and cardamom into fine breadcrumbs. In a food processor, pulse the butter, flour, brown sugar, caster sugar and cardamom into fine breadcrumbs. Weigh out 200g/7oz of this mixture into a bowl for the crumble topping; stir in the oats and set aside. Weigh out 200g/7oz of this mixture into a bowl for the crumble topping; stir in the oats and set aside. Add the egg yolk into the remaining mixture, then pulse in the processor until a dough is formed. Press this dough into the baking tin, ensuring it is spread evenly, then use a fork to prick the base all over. Add the egg yolk into the remaining mixture, then pulse in the processor until a dough is formed. Press this dough into the baking tin, ensuring it is spread evenly, then use a fork to prick the base all over. Bake for 15 minutes, then remove and let cool slightly as you prepare the rhubarb filling. Bake for 15 minutes, then remove and let cool slightly as you prepare the rhubarb filling. To make the filling, combine the rhubarb in a bowl with the cornflour and caster sugar. To make the filling, combine the rhubarb in a bowl with the cornflour and caster sugar. Spread the vanilla custard over the slightly cooled and cooked biscuit base, then layer the rhubarb batons in tight rows. Sprinkle with the oat crumble topping. Spread the vanilla custard over the slightly cooled and cooked biscuit base, then layer the rhubarb batons in tight rows. Sprinkle with the oat crumble topping. Bake for 40 minutes. Take the tray out of the oven and sprinkle the flaked almonds over the crumble topping. Return to the oven for an additional 10 minutes, or until the flakes are lightly toasted and the bake is golden in colour. Bake for 40 minutes. Take the tray out of the oven and sprinkle the flaked almonds over the crumble topping. Return to the oven for an additional 10 minutes, or until the flakes are lightly toasted and the bake is golden in colour. Cool for 20 minutes before slicing into bars. Enjoy warm or chill and enjoy the next day. Cool for 20 minutes before slicing into bars. Enjoy warm or chill and enjoy the next day. Recipe tips These crumble bars keep well if refrigerated in an airtight container for up to 3 days.