Rhubarb & custard blondies

Add custard powder to blondie mix for an extra fudgy texture. Pair with rhubarb for a classic flavour combination, or try swirling in some jam or compote

  • Prep:15 mins
    Cook:55 mins
  • Serves 12
  • Easy

Nutrition per serving

  • kcal 464
  • fat 24g
  • saturates 14g
  • carbs 57g
  • sugars 0g
  • fibre 1g
  • protein 5g
  • salt 0.6g


  • 225g salted butter (or unsalted with a pinch of salt), plus extra for the tin
  • 200g light brown soft sugar
  • 100g caster sugar
  • 150g plain flour
  • 50g custard powder
  • ½ tsp baking powder
  • 3 medium eggs
  • 250g white chocolate chips or white chocolate finely chopped
  • 2 tsp vanilla extract
  • 200g rhubarb (frozen, or canned and drained is fine)
  • 75g caster sugar
  • pink or red food colouring (optional)
  • 4 tbsp ready-made custard (from a carton is fine, or made up from powder)


Frozen or canned rhubarb is available all year round, but while in season, rhubarb can be picked up cheaply in bunches. It freezes well, too – just chop and put in a container in the freezer until you’re ready to make a compote (without the colouring). You can spoon it over porridge, yogurt or make a crumble. It keeps for up to four days covered in the fridge.
If you don't have rhubarb, you can use any jam or compote – swirl through ready-made raspberry jam, or a homemade pear and apple compote for a crumble-inspired blondie. 


  1. For the rhubarb & custard swirl, put the rhubarb and sugar in a wide pan with 2 tbsp water (omit the water if using canned rhubarb). Cook over a medium heat, stirring frequently for about 10 mins, until the rhubarb breaks down and turns jammy. Add a few drops of food colouring if you want a pink rhubarb swirl, but the flavour will still be great if you’re using green-tinged rhubarb. Leave to cool.

  2. Heat the oven to 180C/160C fan/gas 4. Put the butter and both sugars into a pan and put over a low heat. Melt together until smooth and shiny, then remove from the heat, and leave to cool for 10 mins while you sieve the flour, custard powder and baking powder in a bowl. Butter a 20 x 30cm baking tin and line with baking parchment.

  3. Beat the eggs into the cooled sugar and butter mixture, then fold in the dry ingredients until you have a smooth batter. Stir in 150g of the chocolate chips and the vanilla. Pour into the brownie tin, then use a teaspoon to swirl rhubarb compote on top of the batter. Add dollops of the custard, then swirl a skewer or cocktail stick through the compote to create a marbled pattern.

  4. Bake for 35-40 mins until set and the edges are coming away from the sides of the tin, then leave in the tin to cool. Melt the remaining 100g chocolate in short blasts in the microwave or in a bowl set over a pan of simmering water. Use a spoon to drizzle the chocolate over the blondie in a zig-zag pattern. Cut into squares to serve. Will keep for three days in an airtight container, or freeze the squares individually.

Suggested recipes from this collection...