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Mars Bar Slice

Mars Bar Slice has been around for decades in Aussie home cooking, and was hugely popular in the 80’s and early 90’s.

While padded shoulders, perms and neon are best left as memories, this slice is in an entirely different category. It’s just as good today – and I still find it hard to stop at just one slice.

mars bar slice pieces sitting on plate with cloth in foreground

A time before Mars Bars

Mars Bars were not around when Nana Ling created her recipe books, at least not in Australia. I knew this before I started researching.


Well if they had been around, Mars Bar Slice would have surely been in her recipe books along with all the other Aussie classics.

The Mars Bar was first made in 1932 in Slough, England, by Forrest Mars Sr, according to Wikipedia.

It hit Australian shores in the late 1940’s, first being manufactured under licence by another company.

mars bar slice newspaper article

In 1979, Mars set up a manufacturing in Australia’s Ballarat, a time when “the Mars Bar was the main product on the Australian confectionery market.”

These days, it’s still popular but has dropped to our third favourite behind Cherry Ripe and Cadbury Milk Chocolate bars.

Making Mars Bar Slice

To make this recipe, you need just five ingredients:

  • Mars bars
  • rice bubbles (you might call them rice krispies or rice puffs if you’re not from the land down under)
  • butter
  • golden syrup (you can substitute agave nectar, cane syrup or brown rice syrup)
  • milk chocolate.

The exact measurements can be found in the recipe card at the bottom of the post.

You’ll also need a slice tin (around 27 x 17cm), greased and lined, a mixing bowl and spoon and saucepan.

You then just measure out the rice bubbles into a mixing bowl and add the mars bars, butter and syrup to a saucepan.

Heat the ingredients in the saucepan gently until they’re melted and keep stirring until the mixture reaches a smooth, runny consistency.

You then pour this mixture into the rice bubbles and stir quickly to combine.

Spread the mixture into the slice tin and use the back of a spoon to smooth out the mixture.

Melt the milk chocolate and pour over the slice to form the top layer.

Then, it’s into the fridge to set.

Tips for perfect Mars Bar Slice

There are many slight variations of this recipe.

I’ve adapted this one from the the recipe my mum used when we were kids and others I’ve tried since then. I think I’ve created the ULTIMATE Mars Bar Slice recipe.

While it’s a fairly straightforward process, keep these three tips in mind when preparing this no-bake slice.

1. Use good quality ingredients

There are only a few ingredients, so use the best. I use Cadbury chocolate, real Mars Bars, Kellogs rice bubbles, and brand name butter.

2. Use a whisk to get a super smooth melted mixture

When melting the butter, golden syrup and Mars Bars together over heat, the mixture can tend to be clumpy. I use a whisk to stir the mixture towards the end of the melting process and get a super smooth result every time.

3. Use a spoon for an even finish

After pressing the mixture into the tray, use the back of a metal spoon to flatten the slice evenly on top.

making mars bar slice

Mars Bar Slice FAQs

1. Why does it taste so damn good?

It’s that simple but unbeatable combo of rice bubbles, melted Mars Bars and butter… all topped with a layer of chocolate.  

2. How many Mars Bars do you need for the slice?

If you’re a Mars Bar lover like me, make sure you buy your four Mars Bars just before you make the slice. Otherwise, consider buying five!

3. Can you freeze Mars Bar slice?

You could, and I imagine it would be okay for a month or two. I’ve never tested this though because this slice gets gobbled up too quickly in our house.

4. Where do you store it?

It’s best stored in the fridge, especially during the summer months.

However it is okay out of the fridge for a while if you’re planning to take it to a party to share, for example. 

5. How long does this slice last in the fridge?

It will last at least a week stored in an airtight container in the fridge.

6. How long does Mars Bar Slice last in your house?

If it lasts more than a few days, you’re doing well!

7. Are there any other slices as good as this?

This is surely a winner, but you can check out our amazing Cherry Ripe Slice, Caramel Slice and other wonderful slices here.

squares of mars bar slice stacked on plate

Mars Bar Slice

A caramel chocolate 5-ingredient, no-bake slice recipe that everyone will love
4.88 from 33 votes
Print Pin Rate
Course: Dessert
Cuisine: Australian
Keyword: mars bar slice
Prep Time: 30 minutes
Cook Time: 0 minutes
Total Time: 30 minutes
Servings: 24 slices
Calories: 87kcal


  • slice tin (around 27 x 17cm)


  • 4 Mars bars (53 gram bars)
  • 3 cups rice bubbles
  • 60 grams butter
  • 2 teaspoons golden syrup
  • 180 grams milk chocolate (add another 60 grams if you like the chocolate a little thicker)


  • Grease a slice tin (around 27 x 17cm) with butter and then line with baking paper, leaving extra on each side (to pull the slice from the tin once cooked).
  • Measure rice bubbles into a large mixing bowl.
  • Break mars bars into pieces with your hands and put into a saucepan. Add butter and golden syrup.
    mars bar slice ingredients in saucepan
  • Place saucepan on medium heat while stirring to combine.
  • Keep stirring until the mixture reaches a smooth, runny consistency. Use a whisk to stir the mixture towards the end of the process to help get that completely smooth consistency. The mixture should resemble melted chocolate, with no lumps.
    mars bar slice mixture
  • Add mixture to rice bubbles and stir quickly to combine.
  • Spread out mixture in the slice tin, spreading evenly to the edges and then pressing into the tin with the back of a metal spoon. Place in fridge for 1/2 hour.
    pressing mars bar slice into tin with a spoon
  • Melt chocolate in the microwave using 15 second bursts. (check and stir after each burst).
  • Pour melted chocolate over the slice and angle tin from edge to edge to help chocolate reach each side and corner of the slice tin.
  • Place in fridge for 15-30 minutes. Ideally, the chocolate shouldn't be completely set when cutting (it will crack as you're cutting if it's too hard).
  • Once set, remove slice from tin by lifting edges of baking paper, cut into squares and return to the fridge. (And if you've left the slice in the fridge for longer, just let the slice rest at room temperature for half an hour before cutting into squares.)



  1. Read the entire post and recipe card for all the tips and hints.
  2. The most important part of the process is heating the mars bars, syrup and butter gently and then whisking the mixture over the heat to get a smooth texture.
  3. Another tip for perfect Mars Bar Slice: make sure you use good quality ingredients.


Calories: 87kcal | Carbohydrates: 10g | Protein: 1g | Fat: 6g | Saturated Fat: 3g | Cholesterol: 6mg | Sodium: 45mg | Potassium: 31mg | Fiber: 1g | Sugar: 6g | Vitamin A: 355IU | Vitamin C: 2.6mg | Calcium: 3mg | Iron: 1.5mg
Recipe Rating

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Thursday 16th of September 2021

Hi Libby

This is a childhood memory, great recipe. Can you freeze it?

Libby Hakim

Thursday 16th of September 2021

Hi Frejan - yes, you can freeze it for up to a couple of months and just thaw it out before eating. Thanks for the great rating and question - Enjoy!

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