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Mars Bar Slice

A 5-ingredient, no-bake slice recipe that everyone will love.
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squares of mars bar slice stacked on plate

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.

This no-bake recipe is so easy and simple.

Just gather the 5 ingredients and with the tips and tricks outline below you’ll have it ready in 20 minutes flat.

mars bar slice pieces sitting on plate with cloth in foreground

The recipe for Mars Bar Slice

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

How? 

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.

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.

Okay, enough history. Back to the recipe.

This recipe was around during the 1980’s and 90’s and I’m not sure what genius came up with the original recipe.

But they deserve a huge thanks because this has to be one of the best slices around.

There are many slight variations of this recipe.

This recipe has been adapted this recipe 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.

I’ve incorporated a few little tweaks we’ve come up with over the years, especially to the method.

You’ll love this recipe which delivers a slice that is not too crunchy and not too crumbly – both things that disappoint a true Mars Bar Slice connoisseur!

Making perfect homemade Mars Bar Slice: the 5 ingredients

To make this recipe, you’ll need:

  • Mars Bars
  • Rice Bubbles (you might call them Rice Krispies or Ricies 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.

mars bar slice ingredients

What else you need

Apart from the ingredients, you’ll also need:

  • slice tin (around 27 x 17cm), greased and lined
  • mixing bowl and spoon
  • small whisk
  • small heatproof bowl and spoon
  • saucepan.

You use the stovetop and also the microwave when preparing the slice.

When greasing and lining the tin, leave some baking paper overhanging on each side so you can gently ease the slice from the tin to cut it up.

This avoids the difficulty of trying to cut it into squares while still in the tin. So much easier to just lift it out and cut it up!

Making this awesome Aussie slice

Okay, let’s go.

Start by measuring out the rice bubbles into a large mixing bowl.

Break up the mars bars into pieces and add the mars bars, butter and syrup to a saucepan.

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

I swap the spoon for a small whisk towards the end of the process to get a super smooth consistency.

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

Spread it into the slice tin and use the back of a spoon to smooth it out evenly. Make sure you press it firmly into the tin at this step.

Melt the milk chocolate in the microwave using 20 second bursts. Take out and stir for 20 seconds between each burst until you have a runny, smooth melted chocolate.

Pour the melted chocolate over the slice to form the top layer.

Tilt the tray from side to side if necessary to ensure the entire top layer is covered in chocolate.

melted chocolate for mars bar slice

Then, it’s into the fridge to set.

When you’re ready to cut it into squares, take the slice out of the fridge and leave it for about 20 minutes.

If you try to cut it up straight from the fridge the top chocolate layer may crack.

Once you’ve left it out for at least 20 minutes, ease it from the tray using the overhanging baking paper.

Cut into squares using a large, sharp knife.

Tips for perfect results

While it’s a fairly straightforward process, keep these four 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, Kellogg’s rice bubbles, and other brand names.

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

When melting the butter, golden syrup and Mars Bars together, the mixture can tend to be clumpy.

I use a whisk to stir it towards the end of the melting process and get a super smooth result every time.

mars bar slice golden syrup

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.

Make sure you press it firmly into the tin.

4. Don’t attempt to cut the slice straight from the fridge

Avoid cracking in the top layer by allowing the slice some time at room temperature before cutting into squares.

Mars Bar Slice FAQs

1. Why does it taste so damn good?

It’s that simple but unbeatable combo of rice bubbles and melted Mars Bars… 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 can. It should be okay for a month or two in the freezer. This slice gets gobbled up too quickly in our house for freezing, though.

If you do manage to freeze some, remove from the freezer and allow to defrost before consuming.

4. Can you replace the golden syrup?

You can replace the golden syrup with maple syrup, honey or corn syrup. You can also simply omit it.

I prefer the flavour and consistency of the slice with the small amount of golden syrup added to the mix.

5. How do you stop the slice from crumbling or cracking?

If your slice is crumbling you may not have pressed it into the tin firmly enough.

It’s also possible you didn’t melt and combine the mars bar, butter and syrup mixture well enough. Make sure these ingredients are melted and combined over low heat until smooth.

If it cracks as you cut it, it’s too cold. Leave the slice out of the fridge for at least 20 minutes before cutting into squares.

6. Why is my Mars Bar slice hard?

If the slice is too hard to eat, let it soften out of the fridge for about half an hour before consuming.

7. Where do you store it?

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

However it is okay at room temperature for a while if you’re planning to take it to a party to share, for example. 

8. How long does Mars Bar Slice keep?

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

9. How long does this slice last in your house?

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

10. 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, Peppermint Slice, Jelly Slice, Lemon Slice, Rice Bubble Slice, Weetbix Slice and other wonderful slices here.

11. Do you have any variation ideas?

The original is really hard to improve upon, it’s just so good as it is.

However, some people like to add mini marshmallows, Maltesers or M & Ms to the mix.

You can stir these to the rice bubble mixture or sprinkle over the top of the top melted chocolate layer.

At Christmas, I like to buy some Christmas-themed M & Ms and sprinkle over the top to add a festive touch.

christmas mars bar slice

squares of mars bar slice stacked on plate

Mars Bar Slice

A 5-ingredient, no-bake slice recipe that everyone will love.
4.89 from 35 votes
Print Pin Rate
Course: Dessert
Cuisine: Australian
Keyword: mars bar slice
Prep Time: 20 minutes
Cook Time: 0 minutes
Total Time: 20 minutes
Servings: 24 slices
Calories: 87kcal

Equipment

  • slice tin (around 27 x 17cm)
  • mixing bowl and spoon
  • small whisk
  • small heatproof bowl and spoon
  • saucepan

Ingredients

  • 4 Mars bars (53 gram bars)
  • 3 cups rice bubbles
  • 60 grams butter
  • 2 teaspoons golden syrup
  • 240 grams milk chocolate (you can get away with 180 grams, which is one family block of Cadbury's, but the extra 60 grams is ideal)

Instructions

  • 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).
    greased slice tin
  • 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 low 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 firmly 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 20 second bursts. (check and stir after each burst).
    melted chocolate
  • 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). Alternatively, if you've left the slice in the fridge for longer just let the slice rest at room temperature for at least 20 minutes before cutting into squares.
  • Remove slice from tin by lifting edges of baking paper, cut into squares and return to the fridge.

Video

Notes

  1. Read the entire post and recipe card for all the tips and hints. This is an easy recipe, but there are a few tips and tricks to get a perfect result.
  2. The most important part of the process is heating the mars bars, syrup and butter gently and then whisking the mixture over the low heat to get a smooth texture. Make sure the temperature remains low.
  3. Another tip for perfect Mars Bar Slice: make sure you use fresh, good quality ingredients.
  4. Crumbling slice? If your slice is crumbling you may not have pressed it into the tin firmly enough. It’s also possible you didn’t melt and combine the mars bar, butter and syrup mixture well enough. Make sure these ingredients are melted and combined over low heat until smooth.
  5. Cracks in slice on cutting it? You’ve cut it too cold. Leave the slice at room temperature for at least 20 minutes before cutting into squares.
  6. Storing your slice. It’s best stored in the fridge, especially during the summer months. It will last at least a week stored in an airtight container.
  7.  Can you freeze Mars Bar slice? Freeze for a month or two, and allow to defrost once you’re ready to consume.
  8. Can you replace the golden syrup? Yes, with maple syrup, honey or corn syrup. You can also simply omit it.
  9. Make it festive by adding some red and green M & Ms or festive-themed sprinkles.

Nutrition

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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Frejan

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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