“Rhubarb and custard is an iconic flavour combination – whether you think of those boiled sweets (my parents used to adore these) or even just stewed rhubarb topped with fresh custard, the sweet tang you get from the rhubarb, combined with the lovely flavour of custard, it really is amazing,” says blogger and baker, Jane Dunn. “Add these delicious flavours to a blondie traybake and it wins everyone’s favourite bake!”

Rhubarb and custard blondie
(Ellis Parrinder/PA)
Rhubarb and custard blondie
Print Recipe
Nutrition Facts
Rhubarb and custard blondies
Amount Per Serving
Calories 299 Calories from Fat 144
% Daily Value*
Fat 16g25%
Saturated Fat 9g56%
Trans Fat 1g
Polyunsaturated Fat 1g
Monounsaturated Fat 4g
Cholesterol 75mg25%
Sodium 44mg2%
Potassium 129mg4%
Carbohydrates 38g13%
Fiber 1g4%
Sugar 27g30%
Protein 3g6%
Vitamin A 393IU8%
Vitamin C 1mg1%
Calcium 63mg6%
Iron 1mg6%
* Percent Daily Values are based on a 2000 calorie diet.

Rhubarb and custard blondies

An iconic flavour combination
Prep Time10 mins
Cook Time35 mins
Total Time45 mins
Course: Dessert
Cuisine: British
Servings: 16
Calories: 299kcal


  • Saucepan
  • 23cm square baking tin
  • Large bowl


  • 175 g rhubarb
  • 300 g white granulated sugar
  • 2 tbsps water
  • 200 g unsalted butter melted
  • 3 eggs
  • 125 g plain flour
  • 75 g custard powder
  • 200 g white chocolate chips or chunks
  • 100 g custard


  • Chop the rhubarb into pieces, and add to a pan with 50g of the sugar and the water. Place over a medium heat, stirring occasionally, for about five minutes, or until the rhubarb softens. Set aside to cool.
  • Preheat the oven to 180°C/160°C fan and line a 23cm square tin with parchment paper.
  • Put the melted unsalted butter and remaining 250g sugar into a large bowl and beat until smooth. Add the eggs and beat until smooth, then add the plain flour and custard powder and beat until combined. Fold through the white chocolate chips or chunks.
  • Pour the mixture into the tin and spread out evenly. Dollop the rhubarb mixture and custard over the top and swirl through slightly using a cake skewer or knife.
  • Bake the blondies for 30–35 minutes, or until there is an ever so slight wobble in the middle. Leave the blondies to cool fully in the tin before cutting into 16 squares.


I use fresh or tinned rhubarb depending on the season – if using tinned rhubarb, use the syrup from the tin instead of the two tablespoons of water.
You can use ready-made custard, or make up some custard using more custard powder.
You can leave out the white chocolate chips or chunks or swap them for a different flavour of chocolate.
The rhubarb can be swapped for another fruit, such as cherries, blackberries, or even apples!


Calories: 299kcal | Carbohydrates: 38g | Protein: 3g | Fat: 16g | Saturated Fat: 9g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 4g | Trans Fat: 1g | Cholesterol: 75mg | Sodium: 44mg | Potassium: 129mg | Fiber: 1g | Sugar: 27g | Vitamin A: 393IU | Vitamin C: 1mg | Calcium: 63mg | Iron: 1mg

Jane’s Patisserie by Jane Dunn is published by Ebury Press. Photography by Ellis Parrinder.




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Last update on 2022-08-10 / Affiliate links / Images from Amazon Product Advertising API

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