Rhubarb & custard blondies served on a tray

Rhubarb & custard blondies

  • 1
  • 2
  • 3
  • 4
  • 5
(19 ratings)

Prep: 15 mins Cook: 55 mins


Serves 12

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

Nutrition and extra info

  • Freezable
  • Vegetarian

Nutrition: Per serving

  • kcal464
  • fat24g
  • saturates14g
  • carbs57g
  • sugars44g
  • fibre1g
  • protein5g
  • salt0.6g
Save to My Good Food
Please sign in or register to save recipes.


  • 225g salted butter (or unsalted with a pinch of salt), plus extra for the tin



    Butter is a dairy product made from separating whole milk or cream into fat and…

  • 200g light brown soft sugar
  • 100g caster sugar
  • 150g plain flour
  • 50g custard powder
  • ½ tsp baking powder
    Baking powder

    Baking powder

    bay-king pow-dah

    Baking powder is a raising agent that is commonly used in cake-making. It is made from an alkali…

  • 3 medium eggs



    The ultimate convenience food, eggs are powerhouses of nutrition packed with protein and a…

  • 250g white chocolate chips or white chocolate finely chopped
  • 2 tsp vanilla extract

For the rhubarb & custard swirl

  • 200g rhubarb (frozen, or canned and drained is fine)



    Botanically, rhubarb is a vegetable (it's related to sorrel and dock) but its thick, fleshy…

  • 75g caster sugar
  • pink or red food colouring (optional)
  • 4 tbsp ready-made custard (from a carton is fine, or made up from powder)


  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.

You may also like

Comments, questions and tips

Sign in or create your My Good Food account to join the discussion.
kathryndonna's picture
18th Apr, 2020
I have made this twice now and the second time used nectarines cooked down to give a "peaches and cream" effect. Both times it was delicious although it did take a little longer to cook than in the recipe.
lindseyanderson's picture
15th Mar, 2020
These turned out brilliantly! I used tinned rhubarb and swapped to gluten free flour. Also didn’t add custard powder as didn’t have any so added 2 tbsp of ready made custard and a bit more flour. Cooked for 45 minutes in my oven.
16th Feb, 2020
Did GF do a quality control test on this recipe? I cooked it for far longer than recipe stated and turned oven upto 170c and it was still raw in the middle even though it looked & smelled amazing
3rd Mar, 2020
Hi Veronicap1, Really sorry to hear you were unhappy with this recipe. This might be because there was too much liquid in your jam, before it’s added to the blondie mixture. If using canned rhubarb it can hold a lot more water than using fresh, and could cause the batter to be too wet taking longer to cook. The rhubarb should cook down for 10 minutes and become thick and jammy, before being left to cool. I hope you make the recipe again with success! Thanks, Anna
Be the first to ask a question about this recipe...Unsure about the cooking time or want to swap an ingredient? Ask us your questions and we’ll try and help you as soon as possible. Or if you want to offer a solution to another user’s question, feel free to get involved...
Be the first to suggest a tip for this recipe...Got your own twist on this recipe? Or do you have suggestions for possible swaps and additions? We’d love to hear your ideas.
Want to receive regular food and recipe web notifications from us?