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Easy white chocolate chip custard cream blondies with a custard flavoured blondie based, stuffed with custard creams! 

Custard cream blondies

So we have all experienced the absolute wonders that are the blondies already in my blog, but I just couldn’t resist posting another one… this time?! Custard cream flavoured! The absolute best of the best in my eyes. 

I have had so many requests for a custard cream blondies recipe that I can’t actually cope! My biscoff blondies and my bakewell blondies have always been so popular, but I have a feeling these are going to be on another level. 

I have a thing for blondies as they are such an easy traybake to make, but also just so good! They are fudgey, sweet, and incredibly moreish. With a custard twist, they are even better! Honestly, I know you will enjoy them. 


For the base of the recipe, I have stuck to the same idea as my biscoff blondies because I just love it! I am a firm believer in ‘if it ain’t broke, don’t fix it’ and I am in loveeee with these. 

I will say now, as I do in all my blondies at the moment, I do not use a melted white chocolate base. Technically, a blondie is a non-chocolate brownie – so without the cocoa or dark chocolate. They are also known as white chocolate brownies, but I don’t actually like using white chocolate with this recipe! 

I find when adding the melted white chocolate to this recipe changes it and it just doesn’t taste as nice! I will produce a white chocolate one in the future, but for now… please just stick with this recipe as it is. It’s a blonde coloured traybake = blondie! 

Custard powder

But anyway.. I am OBSESSED AS ALWAYS. A little twist for these, is using custard powder in place of cornflour. They do act in a really similar way, but the custard powder brings a flavour of custard, and also the deeper and yellower colour! 

You can of course, use 1tbsp cornflour, but honestly… to stick with the theme you might as well! You get enough delicious flavour from the custard creams which are obviously ESSENTIAL to the bake. And you get some gooey from the white chocolate! 


Like always, my bakes are customisable and delicious – you can use any other biscuit you fancy! I have a recipe for Jammie Dodger blondies on my blog and they are just heavenly!

Honestly, go for it. It’s worth noting that these are rather addictive though, and custard creams are one of my favourite classic biscuits out there! Biscuit blondies are definitely a must try for biscuit lovers everywhere!


Some top tips for baking blondies – like any recipe, nothing is fool proof. I hate that phrase in baking, as there are so many factors that can make a recipe change and not work! For this recipe, a key part is use the correct size tin, and have the correct oven temperature.

I know this sound obvious, but I use this baking tin for this recipe – I’ve had many comments in the past of different tin sizes used, and the recipe hasn’t worked! Some tin sizes can need more than double the mixture for “just two inches bigger a tin”! 


Another super important factor is the oven temp – if you are unsure, get an oven thermometer!! They are the best invention. One of my ovens in the past was 50ºc incorrect, so you can imagine my attempts at baking in that!

It’s always best to bake the blondies so that there is a slight wobble in the middle of the tin. It shouldn’t shake, but a little wobble is perfect. After that, a great tip is to let the blondies cool in the tin, and then whack the tin in the fridge. This creates that beautiful fudgy texture you can see in the photos!

I hope you guys love this recipe – if you have any questions, leave them below in the comments! And if you have a go at the bake, make sure to post a photo on social media and tag me! Jane x

Custard Cream Blondies!

Easy white chocolate chip custard cream blondies with a custard flavoured blondie based, stuffed with custard creams!
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Category: Traybakes
Type: Blondies
Keyword: Custard Cream
Prep Time: 15 minutes
Cook Time: 30 minutes
Cooling Time: 2 hours
Total Time: 2 hours 45 minutes
Servings: 16 Pieces
Author: Jane's Patisserie


  • 200 g unsalted butter (melted)
  • 125 g white granulated sugar
  • 125 g light brown sugar
  • 3 medium eggs
  • 1 tsp vanilla extract
  • 275 g plain flour
  • 35 g custard powder
  • 200 g white chocolate chips
  • 200 g custard creams (chopped)


  • Preheat your oven to 180ºC/160ºC Fan and line a 9x9" square tin with parchment paper.
  • In a large bowl, add the melted butter, white granulated sugar and light brown soft sugar and beat until smooth.
  • Add in the eggs and vanilla extract and beat again until smooth.
  • Add in the flour and custard powder and beat until a thick blondie mixture is made - it really doesn't take long to create this mixture!
  • Add in the custard creams and white chocolate chips and fold together.
  • Bake the custard cream blondies in the oven for 25-30 minutes, or until there is a slight wobble in the middle. (See notes below)
  • Leave to cool in the tin, or on a wire rack.
  • As an optional extra, you can 'set' your blondies in the fridge for an hour or so to help with the texture! ENJOY!


  • The bake time can vary - please make sure your oven is on the correct setting, and check from 22+minutes and onwards till they are baked! These took 25 minutes in my fan oven. 
  • If they turn out cakey, they are over baked - that's all! Bake for a little less time next time. 
  • One top tip is if they've been in for the 25-30 minutes, and you're still not sure, let them cool outside of the oven fully and then put them in the fridge for at least an hour to 'set'. It can firm them right up! Over night in the fridge is best. 
  • I use the birds custard powder
  • These will last in a container for 4-5+ days
  • I keep them at room temperature. 
  • I recommend this tin!


Find my other Recipes on my Recipes Page!

You can find me on:

J x

© Jane’s Patisserie. All images & content are copyright protected. Do not use my images without prior permission. If you want to republish this recipe, please re-write the recipe in your own words and credit me, or link back to this post for the recipe.


  1. Charlotte on June 9, 2024 at 8:08 am

    Hello, I love your recipes! I only have Large eggs so will I still use 3? Or drop it to 2. Thanks

  2. Chloe Hacker on March 1, 2024 at 7:21 pm

    Does instant custard work the same as custard powder?

  3. Claire on January 25, 2024 at 5:50 pm

    Wow! My new favourite thing! These were delicious and worked perfectly. Your recipes are always super easy to follow and a success. I was hoping to bake another tray tonight but I am out of light brown sugar….could I use gold caster or Demerara instead?

  4. Zoe on August 1, 2023 at 9:27 pm

    5 stars
    Love this recipe! I swap my custard creams for a whole pack of mars bars 😂🙊
    Could I use gluten free flour for this too?

  5. Zoe Jennings on July 28, 2023 at 10:00 pm

    5 stars
    Can I make these with gluten free flour please?

  6. Kerry on April 30, 2023 at 7:14 pm

    I made these today and really unsure at the moment if they’ve worked! They had a tiny wobble when I took them out of the oven, I let them cool then started to chip them but they seemed very wet?
    I put them back in the oven for 8-10 mins then saw the fridge tip so they’ve been in there for just Iver an hour- should they be firming up by now? Still seem quite wet so not sure whether to just start again! 😔

    • Jane's Patisserie on May 3, 2023 at 8:21 am

      Hiya! Once something has been out the oven and cooled, do not add it back to the oven to continue baking as it doesn’t work. The only way to tell is to cut them and see if they have, but if you used the correct size tin it may have simply meant they needed a couple extra minutes baking time x

  7. Dawn on August 8, 2022 at 3:53 pm

    Hi just a quick one could I use ready made custard and add in more flour instead of the custard powder only because I don’t have the money nothing at all to go and buy some and I already have the custard in the cupboard. I’m making them today for a party tomorrow. I have all the other ingredients.
    How would I do this?
    Thank you

    • Jane's Patisserie on August 12, 2022 at 12:29 pm

      Hiya! Unfortunately, it does not work like this! So sorry, hope they turned out good in the end! x

  8. Jenna on April 26, 2022 at 12:13 am

    Is it possible to make these in a 9×13 pan? Would the recipe be altered to 1.5 or just double the recipe?

  9. Zee on February 25, 2022 at 3:43 pm

    Hi Jane,

    Being on autopilot I’ve added 1 tblspn of Corn Flour & 35g of Custard Powder – is this going to dry the blondies out? Would you recommend starting again?


  10. Tracy on February 10, 2022 at 7:32 am

    5 stars
    Hi Jane love your book 🥰 my tin is 18.5cm x 31cm which is slightly bigger Should I reduce the cooking time or change temperature? Thanks in advance x

  11. Fran xx on February 2, 2022 at 4:08 pm

    I don’t have white choc chips can
    I just chop white chocolate up?

    • Jane's Patisserie on February 3, 2022 at 1:33 pm

      Hiya! Yes you can! Enjoy! x

  12. Amy on February 2, 2022 at 8:30 am

    Hi! Could I leave out the custard powder and add the foodie flavours (custard) flavouring instead? If so would I add more flour to make up for the lack of custard powder please?

    • Jane's Patisserie on February 3, 2022 at 1:30 pm

      Hiya! Replace the custard powder with the flavouring and 25g more flour. Hope this helps! x

  13. Jessica on November 20, 2021 at 4:02 am

    Can these be frozen? If so how long for?

    Thanks in advance!

    • Jane's Patisserie on November 25, 2021 at 11:40 am

      Hiya! Yes absolutely – you can freeze these for up to 3 months! Hope this helps! x

  14. J Wright on October 5, 2021 at 6:03 pm

    5 stars
    So easy and absolutely delicious! A winner all round. Will also try them with different biscuits and chocolate but for now these are simply wonderful.

  15. R on October 1, 2021 at 3:04 am

    If I wanted to make a bigger batch in bigger trays what would the measurements be? In like a rectangular tray instead of a 9×9

  16. Jeroen on September 28, 2021 at 5:40 am

    If you’re in The Netherlands/Belgium the Lu Prince vanilla cookies might be a nice alternative for custard creams.

    • Nadia on January 4, 2024 at 3:26 pm

      Thank you so much from Belgium!

  17. Emily on September 20, 2021 at 6:29 pm

    Hi Jane I’m just wondering why all of your blondie recipe’s generally use the same volumes of basic ingredients aside from the raspberry and white chocolate blondies which have more butter but less sugar and flour? I’d just be interested to know if there was a science behind it!

    • Jane's Patisserie on September 23, 2021 at 10:58 am

      They are two completely different recipe bases and methods!

  18. Rachel on September 16, 2021 at 7:19 pm

    5 stars
    This didn’t last long! My 2 boys and husband devoured it!

  19. Judles on September 6, 2021 at 11:15 pm

    5 stars
    These look fabulous and will be one of my next bakes! I wanted to ask you if I could use your Biscoff blondie recipe as a base for a Nutella blondie by just switching the Biscoff for Nutella? Thanks x

  20. Meg on September 6, 2021 at 9:53 am

    This looks delicious. We don’t get custard creams here but we do get bourbon biscuits and I think I’ll try out a bourbon biscuits brownies instead? Do you think it’ll work if I substitute white chocolate with dark chocolate instead?

    • lilywp on September 22, 2021 at 4:25 pm

      Hiya! Yes you could try using Bourbon biscuits, or you can try adding them to one of my other brownie recipes! Hope this helps! Team Jane x

  21. Jayne Dursley on September 5, 2021 at 3:12 pm

    Hi, can I use stork instead of butter plz

  22. Lyn Cusack on September 5, 2021 at 9:18 am

    Do I need to use white chocolate chips in this recipe.
    Sadly due to medical reasons I am unable to eat any chocolate.

  23. Stacy Ancel on September 4, 2021 at 4:37 pm

    5 stars
    In the USA we don’t have anything called “custard creams.” Can you give us an idea of what they are so we can find a substitute? Are they a cookie with cream filling like Golden Oreos? What are they? Thank you!

    • Samantha on September 6, 2021 at 10:06 pm

      I think a golden Oreo would work 🙂 xx

    • Melissa Bassil on September 6, 2021 at 11:01 pm

      Custard creams are a popular cookie in the UK. They’re a sandwich type cookie. Think of it like an Oreo but with a vanilla cookie rather than chocolate, and the filling is a bit less sweet than that in an Oreo.

    • Judles on September 6, 2021 at 11:20 pm

      5 stars
      Stacey, I would think that you could use the golden Oreos as they’re similar and you might be able to get a custard or vanilla extract/essence on say Amazon?

  24. Janet C on September 4, 2021 at 10:06 am

    I’m in the U.S. and don’t know what custard creams are…the ones you say to chop.

    • Jen on September 4, 2021 at 1:42 pm

      Custard creams are a biscuit/cookie we have in the UK x

    • Melissa Bassil on September 6, 2021 at 11:02 pm

      Please see my reply to Stacy Ancel, above.

    • Kelly H on September 10, 2021 at 12:09 pm

      Custard creams are a similar biscuit/cookie to golden Oreos x

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