
I’ve two prominent memories from my childhood that involve Mars Bars. Random, I know. But being such a well-known and well-loved chocolate here in the UK, I doubt I’m the only one! And if you have never had a Mars Bar (is that even possible?!) you are missing out – but fear not, this Mars Bar Slice is the perfect introduction to a life-long chocolate bar romance.
Mars Bars and I got off to a rocky start… The first memory I have is perhaps not an actual memory, but an incident I have been reminded of my entire life – so much so that it feel likes a memory now! That would be the fateful day my sister tried to kill me, as a mere baby, by giving me a treatsize Mars Bar whilst I sat in my bouncy seat. Of course, I started to choke and it was up to Granny to resolve the situation with a wallop to my back, as well as giving my murderous 2 year old sister a good telling off!
The second memory is a slightly cheerier one. I remember my Dad (our beloved Papa!) having a Mars Bar one day when I must have been about 4 or 5 years old. I asked him to try it, loved it and at some point after that I recall being in the chippy with him where he bought me one just for myself! I still remember it being the older packaging and there must have been some sort of promo or competition on the wrapper, as it also had colourful design across it too.
What could be described as a perfected chocolate bar (aside from it’s shrinking size…) – chewy caramel, soft nougat and delicious chocolate – it’s hard to imagine how you could make it any better than it already is. But to do so is actually incredibly easy!
Melt it with some butter, mix in some rice krispies, top with chocolate and bish-bash-bosh you have the most incredible tray bake which is guaranteed to be a crowd pleaser! I give you, Mars Bar Slice!
Ingredients
Butter or Margarine
Either will do and it’s personal preference to which you choose. The butter/margarine helps the Mars Bars when melting and stops them from becoming overly claggy.
Mars Bars
An essential ingredients in Mars Bar slice! Whatever size Mars Bar you use, just make sure they come to the total weight listed in the recipe.
Rice Krispies
They can be branded or store-own rice crispies, it doesn’t matter at all. They – along with the melted Mars Bars and butter/margarine – are what makes up the bulk of this Mars Bar Slice. The perfect combination of sweetness, sticky caramely-nougat and crispies crunch.
Milk Chocolate
As if the Mars Bars weren’t enough, you also want a generous layer of chocolate on top, to finish this sweet little tray bake off.

Since the size of Mars Bars have changed, this recipe is spot on to fit my baking tray. I followed my mums recipe from the sixties and struggled with it recently, so thanks for the new measurements!
Mars Bar Slice
Ingredients
- 115 g Butter or Margarine
- 230 g Mars Bars (roughly chopped)
- 100 g
Rice Krispies - 250 g Milk Chocolate
Instructions
- Line a 11x7inch (27.9×19.8cm) inch baking tray with some greaseproof paper and set aside.
- In a large bowl, melt the butter/margarine and Mars Bars over a bain marie, or in short bursts in a microwave.
- Add the rice krispies to the melted ingredients and mix well, ensuring all are coated.
- Tip into your prepared baking tray and push down with the back of a spoon, ensuring an even finish right into the corners. Set aside.
- Melt the milk chocolate over a bain marie, or in short bursts in the microwave, before spreading over the top of your rice crispy base.
- Place into the fridge to set for at least a few hours or ideally overnight. Cut into your desired portion sizes to serve.

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Since the size of mars bars have changed this recipe is spot on to fit my baking tray .I followed my mums recipe from the sixties and struggled with it recently so thanks for the new measurements
IS this freezable at all??
Excelent recipe
Hi. I’ve tried twice in the past to melt Mars Bars, with no success. I tried in a bain marie, and in a microwave. All because I had A Mars Bar slice in a lovely cafe in Scotland while on holiday last year, so thought I’d try myself. Does the butter make it easier to melt? It was just a stiff claggy lump when I tried. I can’t wait to replicate them for myself and my kids thanks. Claire
I add golden syrup when melting the Marsbars just a couple of spoonfuls and it helps to stop it all clagging together x
I definitely use golden syrup In mine to hold it together and it’s been no problem
Just put a 2 tablespoons in and it should be ok
Hope this helps
fantastic!!!!!!
I would love to make traditional Scottish shortbread but I’m not sure how to knead and temperature of oven.
I’ve made before but turned out rock hard!!!! I think I need a good recipe and good technique!
can you please help?
Made twice now and beautiful, i just melt in microwave
500g plain flour
500g butter
250g cornflour
250g icing sugar
Cream butter a little. Add dry ingredients and mix until paste forms. Roll on lightly floured board and cut to size. Bake for 12 -14 mins at 155 c. Sprinkle with caster sugar when baked.
Hello Claire (from March ’20). You have to have a bit of patience when melting MarsBars – suggest you cut the bars into quite small pieces and I’m sure the butter will also help. Keep stirring with wooden spoon.. Hope that helps – Glynis
How long will they last once made? And where do I store them please?
Last? If it’s anything like my house they’ll be gone in 5 minutes! Store in airtight container if you manage to salvage any