Go Back
Rhubarb and custard blondies

Rhubarb and custard blondies

A classic blondie filled with white chocolate chunks and swirled with jammy stewed rhubarb and creamy vanilla custard.
Prep Time 30 mins
Cook Time 30 mins
Total Time 1 hr
Course Dessert
Servings 12 slices


For the rhubarb

  • 200 g rhubarb chopped into 4cm pieces
  • 100 g caster sugar
  • 1 tsp vanilla bean paste I like Taylor & Colledge
  • Few drops red food colouring
  • 2 tbsp water

For the blondies

  • 190 g plain flour sifted
  • 20 g Bird's Eye custard powder
  • 1.5 tsp baking powder
  • 170 g unsalted butter
  • 300 g light brown sugar
  • Pinch fine sea salt
  • 1 tsp vanilla bean paste I like Taylor & Colledge
  • 1 large egg at room temperature
  • 100 g white chocolate roughly chopped into chunks
  • 100 g ready-made vanilla custard


To make the stewed rhubarb

  • Cut the rhubarb into 4cm pieces and place in a medium-sized saucepan.
  • Add the sugar and vanilla, along with 2tbsp water and place on a low-medium heat on the hob.
  • Leave to simmer, stirring every now and then, for 10 minutes.
  • Add a few drops of red food colouring if you want that signature pink colour and stir thoroughly. Set aside to cool.

To make the blondies

  • Preheat your oven to 160C / 320F and adjust a rack to the middle shelf.
  • Grease a 9x9 inch square tin with butter and line with baking parchment.
  • In a medium bowl, sift the flour, custard powder and baking powder then mix to combine.
  • In a medium saucepan, melt the butter and sugar over a low heat with a pinch of salt, then remove from the heat and leave to cool completely.
  • Once the mixture has cooled, transfer it into a large bowl and whisk in your egg.
  • Add the flour mixture, stirring until just combined then add the chopped chocolate mixing until everything is nicely incorporated.
  • Using a rubber spatula, swirl through the jammy stewed rhubarb and vanilla custard, leaving a little to dollop over the top.
  • Transfer the batter into the prepared tin and smooth into an even layer. If you're left with a little rhubarb mixture and custard, dollop onto the top of the blondie mix and use a knife to swirl.
  • Bake for 25-30 minutes until golden and bubbling.
    Partille N.B. The rhubarb will have thickened slightly, and the custard will brown a little. While it may look a little wet in the centre, the blondies will continue to cook once removed from the oven.
  • Remove from the oven and leave to cool in the tin for at least 15 minutes.
  • Lift the blondies out of the tin and transfer to a wire rack to cool completely then slice and enjoy!
Keyword blondies, brownies, caramel, chocolate, custard, rhubarb, spring, traybake, vanilla, white chocolate