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A delicious no-bake mars bar crispy square with marshmallows, mars bar, chocolate and Rice Krispies.

Say hello to your new favourite no-bake traybake recipe full to the brim of all things mars bar. They are glorious, they are delicious, and you will adore them. 

Old school recipes 

I have made many a tray bake recipe in my time on this blog, and they’re all delicious – as well as many cupcake recipes and so on! However, I realised that none of these are really suited for ‘kids baking’ or would be what some would consider child friendly as they use mixers and such.

These are chewy, crunchy, sweet, and soft all in one – I love to drench by crispy squares in chocolate, and add even more chocolate with all the different sprinkles – how can you resist?! They’re so easy and tasty to make!

Also – these went down an absolute storm at where my parents work – which is in education, with all adults being the taste testers and everyone LOVED them! Some people saying stuff like “takes me back to my childhood” which is ideal! I really hope you guys like these, and that if you make them with your kids – that they like them too!

Mars Bar recipes

I love Mars Bars, evident by my Mars Bar chocolate mousse recipe, but these are simply delightful. When I was little, Rice Krispie cakes were an absolute must at a bake sale, or at a party – and they still are now. They are very iconic when it comes to the chocolate bar world. 

I’ve posted my no-bake mars bar cheesecake, my mars bar brownies before and my mars bar fudge and I genuinely can’t get enough of all of them. I just adore the mix of the thick caramel, the nougat and the chocolate it’s all wrapped in and I think it just mixes into various bakes so well. 

Crispy squares 

When it comes to crispy squares like this, they are quite simple. I have a few different ones such as my Nutella Rice Krispie treats, and my biscoff Rice Krispie treats, but I love these ones even more because of the mars bar in the base of the recipe. 

  • Mars bar – any sized mars bar chopped into 150g worth is perfect
  • Marshmallows – mini or regular marshmallows work, generally mini marshmallows are easier to melt down but whatever you have in the cupboard is okay 
  • Butter – a block butter is best so that it doesn’t split or ruin the mix, I generally avoid baking spreads or margarines in these recipes 
  • Rice Krispies – rice pops, cocoa pops, any kinda pop works if you want a chocolate base or plain base, it doesn’t matter. 


The decoration for a bake like this is entirely optional. I always like to take things to far when it comes to baking, but I also like to show different ideas. This beauty is no-bake, but it’s super versatile. 

  • Chocolate – I use milk chocolate for this, but white chocolate, dark chocolate or a mix of chocolates work. 
  • Mars Bar – I add some extra bits of mars bar on top, chopped small, just because 
  • Sprinkles – and I add some sprinkles on top as well. These are optional as well. 

Tips and Tricks 

  • These will last for 4-5+ days at room temperature 
  • You can freeze these for 3+ months 
  • If you don’t want to use mars bar, you can use 250g of marshmallows and 100g of milk chocolate 
  • I use this 9″ square tin for all of my traybake recipes 

Mars Bar Crispy Squares!

A delicious no-bake mars bar crispy square with marshmallows, mars bar, chocolate and Rice Krispies.
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Category: Traybakes
Type: Rice Krispie Treats
Keyword: Mars Bar
Prep Time: 20 minutes
Cook Time: 10 minutes
Setting Time: 2 hours
Total Time: 2 hours 30 minutes
Servings: 16 squares
Author: Jane's Patisserie


  • 150 g Mars Bar chopped
  • 200 g mini marshmallows
  • 50 g unsalted butter
  • 225 g Rice Krispies/Coco Pops
  • 250 g milk chocolate
  • extra mars bar
  • sprinkles


  • Line a 9x9inch square tray with parchment paper and leave to the side
  • In a medium sized pan, add your small mars bar chunks, mini marshmallows and unsalted butter
  • Heat on a low heat, stirring frequently until the mixture has melted. At first it may look lumpy but after a while and a bit of beating it'll be smooth
  • Pour in the Rice Krispies/Coco Pops in to a large bowl then pour the smooth melted mixture on top
  • Mix together until all of the Rice Krispies are covered evenly- this can take a bit of welly but its worth it!
  • Press down into your tray evenly and then pour over some melted milk chocolate
  • Decorate with small pieces of chopped mars bar and sprinkles if you fancy
  • Leave the bars to set for a couple of hours, and then portion and enjoy.


  • This is a delicious treat that you can make with your kids - I like using mars bars, as they were a favourite treat of mine when I was little, but if you don't like them or can't get them then use 250g mini marshmallows, and 100g chocolate chips!
  • These last 2-3days in an airtight container!
  • You can make them into individual crispy cakes just as easily if you prefer!
  • I use 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. Claire on December 2, 2022 at 8:07 pm

    Well that was a workout mixing it up and pressing it into the tray!

  2. Jess on June 6, 2022 at 7:30 am


    These are delicious – thanks!

    Can you freeze them?

    • Jane's Patisserie on June 6, 2022 at 12:09 pm

      Yes absolutely you can, for up to 3 months! Hope this helps1 x

  3. Mightyscott on April 30, 2021 at 3:47 pm

    Hello! Marshmallows aren’t vegetarian but marshmallow fluff is, have you tried this with fluff instead of actual marshmallows? Do you think it would work with equal weights? Many thanks- love your recipes!

  4. Tri on February 7, 2021 at 9:29 pm

    Hi Jane.

    What other chocolate could I use instead of a Mars Bar? That wouldn’t cause a problem of it being too hard when cutting

    • Jane's Patisserie on February 8, 2021 at 8:53 am

      This recipe is designed to use the mars bar as the base – the only thing that could work that is similar enough is snickers?

  5. Kath on May 25, 2020 at 4:10 pm

    I made these this weekend but didn’t have mars bars so went for 3 double deckers instead…….. they are lovely. However, when cutting them they weren’t easy to do. They didn’t cut neatly and seemed too hard to cut. Do you have any tips or know where I went wrong please ?

    • Jane's Patisserie on May 25, 2020 at 4:58 pm

      It’s probably because of the double deckers – as they don’t have as much ‘soft’ inside them as a mars bar, it made the mix a bit firmer! x

  6. Rachel on April 3, 2020 at 3:04 pm

    Can I use large marshmallows if I haven’t got mini ones

  7. Jen on June 17, 2018 at 7:13 pm

    Do these need to be stored in the fridge?

  8. Mark on April 10, 2018 at 10:05 am

    Can’t wait to start making some of your recipes, they look amazing. Just a shame you don’t seem to offer printable versions of the recipes you post as it means having to work out which pages to print without printing about 12 pages, and sometimes parts of the recipe gets cut off meaning I have to copy and paste into Word to print them.

    • Jane's Patisserie on April 10, 2018 at 10:07 am

      If you noticed on all my recent recipes, there are printable versions. I have over 350 recipes on my website, so it takes time. I have to now pay for a part of my website to be able to do the printable versions, so you’ll just have to be patient.

  9. Abida Aslam on February 11, 2018 at 2:55 pm

    Your work is amazing!

  10. Linda on October 24, 2015 at 11:01 am

    Oh they are sooo good. I needed to get rid of my cocoa pops and this recipe was perfect for that. 🙂

  11. abbiosbiston on October 7, 2015 at 12:45 pm

    I love rice krispie squares. The best ones I ever managed to make had peanut butter in them and they were irresistible!

  12. Lauren at Knead to Dough on October 2, 2015 at 1:23 pm

    Also, totally off topic but who designed your picture? 🙂 I’ve seen a few similar ones about and was contemplating getting one done!

    • Jane's Patisserie on October 2, 2015 at 4:55 pm

      A girl called Morgane Carlier did 🙂 she’s @morganeca on Instagram!

    • Lauren at Knead to Dough on October 3, 2015 at 12:32 pm

      Thanks Jane!

  13. Kim @sweetontreats on October 2, 2015 at 11:32 am

    Love these!!! ?

  14. Lauren at Knead to Dough on October 2, 2015 at 10:37 am

    I’m starting to think you’re a Mars Bar addict, Jane! These look scrummy though 🙂 I actually have a Terry’s Chocolate Orange crispy cake coming up next Tuesday too, great minds think alike!

    • Jane's Patisserie on October 2, 2015 at 4:57 pm

      Hahah I am, although I’m more of a chocolate orange addict ? and thanks! I look forward to seeing your recipe!

    • Lauren at Knead to Dough on October 3, 2015 at 12:33 pm

      Thanks Jane! It’ll be up this Tuesday 🙂

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