Perfect Mars Bar Slice (best ever!!!!)

This perfect Mars Bar Slice recipe is so simple and works out perfectly every single time. 10 minutes prep time, completely no-bake AND with conventional and Thermomix instructions. Watch the video to see how easy it really is!!

Mars Bar Slice

I’m not the kind of girl that will walk into a supermarket and buy a Mars Bar to eat (not that there is anything wrong with that, I just usually choose a Turkish Delight instead!). Add to that the fact that I never really eat a bowl of Rice Bubbles for breaky (I’m more of a muesli girl). BUT I do NOT ever stick my nose up at eating Mars Bar slice. Never ever. Watch my video and you’ll see why…

So what is it about Mars Bar Slice that makes it sooooo darn good?

A) You don’t need many ingredients – which is great for people like me who even when armed with a grocery shopping list still somehow manage to forget things!

B) It’s super fast to make… I’m talking 10 minutes!! Perfect for when you have other important things to do like cook dinner, fold washing… and watch Netflix!

C) You don’t even need to turn on the oven (which means you can spend your electricity bill savings on shoes… done. done and DONE!).

D) It’s so easy that you could virtually make it with your eyes closed – go on, try it… I dare you!

Mars Bar Slice

But seriously, if you’ve never tried to make Mars Bar Slice before, you have no idea what you’re missing out on… it’s freaking AMAZING!!!

Mars Bar Slice

On a random side note, I saw a piece of Mars Bar Slice in a cafe on the weekend for $4.50… for one teensy piece! Two pieces would have paid for the ingredients to make a whole slice. Crazy stuff!!! And anyway, everything tastes better when it’s homemade, don’t you think?

Mars Bar Slice


For more easy slice recipes, check out our NO-BAKE BARS & SLICES EBOOK packed with 17 of our most popular recipes (available in both conventional and Thermomix versions) for just $10.00.

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Mars Bar Slice

Mars Bar Slice - Conventional Method

This perfect Mars Bar Slice recipe is so simple and works out perfectly every single time. Conventional and Thermomix instructions included.
Course Mars Bar Slice
Cuisine Slices
Prep Time 10 minutes
Total Time 10 minutes
Servings 16
Author Bake Play Smile


  • 75 g butter
  • 3 X 52g Mars Bars chopped
  • 1 tbs golden syrup
  • 3 cups rice bubbles or any puffed rice
  • 250 g milk chocolate melts
  • 20 g coconut oil or vegetable oil (optional)


  1. Grease and line a 18X22cm rectangular slice tin with baking paper and set aside. 

  2. Melt the butter, two of the Mars Bars and golden syrup on low heat in a saucepan (or in 30 second bursts in the microwave on 50% power). Please note: the Mars Bars will not melt - that is fine!

  3. Mix until the butter and golden syrup are smooth.

  4. Stir in the rice bubbles and the third Mars Bar (chopped).
  5. Press mixture firmly into the prepared tin. 

  6. Place chocolate pieces and coconut oil/vegetable oil in a heatproof bowl.

  7. Microwave on medium for 3 minutes, 50% power, or until just melted, stirring every 30 seconds with a metal spoon. Stir until smooth.

  8. Spread over slice and refrigerate until firm.

  9. Remove slice from the refrigerator about 1 hour before cutting into squares with a warm knife.

Recipe Notes

Adding coconut oil or vegetable oil to the melted chocolate will help with spreading and slicing, however it is entirely optional. 


Mars Bar Slice

Mars Bar Slice - Thermomix Method

The ultimate Mars Bar Slice... made in the Thermomix!

Course Slices
Cuisine mars bar slice
Prep Time 10 minutes
Total Time 10 minutes
Servings 16 pieces
Author Lucy Mathieson


  • 75 g butter
  • 3 X 52g Mars Bars chopped
  • 1 tbs golden syrup
  • 3 cups Rice Bubbles (or any puffed rice)
  • 250 g milk chocolate
  • 20 g coconut oil or vegetable oil (optional)


  1. Grease and line a 18X22cm rectangular slice tin with baking paper and set aside. 

  2. Place 2 of the chopped Mars Bars, butter and golden syrup into the Thermomix bowl. Melt on 60 degrees, Speed 2 for 3 minutes.

  3. Add the rice bubbles and the remaining Mars Bar. Mix on Reverse, Speed 2, 15 seconds or until completely combined.

  4. Press the mixture into the prepared tin.

  5. Place the chocolate melts into a clean TM bowl. Melt on 50 degrees, Speed 3 for 2-3 minutes (scraping down the sides of the bowl occasionally).

  6. Pour the melted chocolate over the slice and place back into the fridge to set.

Recipe Notes

Adding coconut oil or vegetable oil to the melted chocolate will help with spreading and slicing, however it is entirely optional. 




40 thoughts on “Perfect Mars Bar Slice (best ever!!!!)”

  1. Genevieve says:

    This looks delicious Lucy!!
    I’m finding myself doing so much more baking since I’ve started reading your blog!

    Today I made a yummy Peppermint Crisp slice that I think you’d love… I’ll have to bring you in a piece for the team meeting!

    1. Bake*Play*Smile says:

      Oh please do!! I am on such a mint craving lately! Hey it’s people like you and your brilliant chocolate mud cake that get me all inspired! 🙂

    2. Shannon Butler says:

      Recipe please?

      1. Bake Play Smile says:

        Hi Shannon, if you scroll down to the bottom of the post, you’ll find the recipe there! xx

  2. Christine says:

    Hi Lucy,
    I am loving all of your recipes on here! I made this one with the new Honeycomb Mars Bars and it was also delicious!

    1. Bake*Play*Smile says:

      Hi Christine,
      Thank you so much! I still can’t quite believe people are actually reading my little blog!!! Yummy!!! A piece of that slice sounds delicious right about now… Perfect with my cuppa!! I will definitely have to try the honeycomb variation…mmmm it sounds amazing!!!!

  3. Lisa @ Mummysundeservedblessings says:

    I made this last week and didn’t think to use my Thermomix! Such a good idea. I will look this up next time. Thanks xx

  4. Cass says:

    Actually, this tastes much better if you skip the butter and golden syrup, add another Mars Bar and use Cadburys chocolate over the top (very important that).

    I have seriously had people not be able to stop themselves eating more, even if they are full, just by making these substitutions.

    1. Bake Play Smile says:

      Hahaha I love these tips. Anything that involves more Mars Bars and chocolate has to be a good thing!

  5. Claire says:

    To make these even better, stir in some mini marshmallows when you put in the Rice Krispies. I don’t let them melt completely so there are bits of mallow through the buns. Yum!

    1. Bake Play Smile says:

      Oh thats such a brilliant idea! Yum!!

  6. Erin Goodman says:

    This is so yummy! Everyone loved it. Would you be able to give some advice as to how to cut it so perfectly. Mine all broke apart, shattered on top and crumbled away at the bottom when I tried to cut it.

    1. Bake Play Smile says:

      Hi Erin, Oh I’m so glad you guys enjoyed it. Sure thing! Check out these tips:

      1. Erin Goodman says:

        Thank you! Just made the malteser slice. Yum!

        1. Bake Play Smile says:

          Yay! So glad you enjoyed it xx

  7. Hey thanks for the mars bar slice recipe. Have not made it in years and yours is the closest recipe I could find just like the way I used to make it. About to make this with my kids now – it’s school holidays and it’s raining. I will let you know how it goes Im sure they are going to love it!!!

    1. Bake Play Smile says:

      Yay! Good luck!

  8. pamela says:

    can’t wait to try These yummy slices

  9. Eleanor says:

    This a real hit and have made it whenever there is a “bring a plate” event for my kids. At this time of the year, I make a Christmasy variation and use white chocolate for the to and sprinkle red or green sugar dust while the chocolate is still soft. Yum!

    1. Bake Play Smile says:

      What a great idea! I’m going to have to try that next time!!

  10. Adam quirk says:

    Me and my girlfriend Vanessa made these delicious slices together and it was completely awesome , it was after eating the first bite she declared to me that I was her boyfriend and she loves me
    I then told her that you Vanessa are my girlfriend and I love you too …

    Thank you America

    1. Bake Play Smile says:


      1. Lily miller says:

        Yummy as I’m totally in love with mars bar slice now that I’ve tasted it. I recommend it for the kids to make.

        1. Bake Play Smile says:

          Fantastic!! It really is such an easy one for the kids to make!

  11. Nerida says:

    I made the Mars Bar Slice (doubled the recipe) for all the boys at work. OMG!!!! It was gone in seconds!
    Thank you.

  12. Heather says:

    Thank you for this recipe. I just made it but I did not use golden syrup and I got a big handful of Malteasers and crushed them up and sprinkled them in the top.

    1. Bake Play Smile says:

      YUM!!!!! What a brilliant idea!

  13. Carol says:

    I wood like a recipe for a good Mars bar slice

    1. Bake Play Smile says:

      Hi Carol, you’ll find the recipe at the bottom of the post. xx

  14. Justin says:

    I recommend cutting into whatever size pieces you want with a sharp knife or cleaver whilst it is still slightly warm on the tray. This way it doesnt shatter. I put it in the fridge for a few minutes first. You want it to set a bit but not rock hard.

  15. Jason says:


    I usually make my slice with a layer of caramel on top of the rice bubble base the chocolate on top of that but I always have trouble with the base being a bit too hard, any ideas on how to stop it from being so solid?

    1. Bake Play Smile says:

      Hi Jason, hmm no I’m sorry I can’t help! That’s different to the way I make it – and I don’t find this base is too solid!

  16. Tracey says:

    Coming from the uk I was wondering if you can tell me how many grams is in a cup? Love the sound of the mars bar slice as it’s one of my favourite chocolate bars
    Oh & seeing as you like Turkish Delight you might want to try these – Turkish Dekight Rocky Roads

    100g butter, roughly chopped
    300g dark chocolate, broken into squares
    3 tbsp golden syrup
    140g rich tea biscuit, roughly crushed
    12 pink marshmallow, quartered (use scissors)
    2 x 55g bars Turkish delight, halved and sliced


    Gently melt the butter, chocolate and syrup in a pan over a low heat, stirring frequently until smooth, then cool for about 10 mins.
    Stir the biscuits and sweets into the pan until well mixed, then pour into a 17cm square tin lined with foil and spread the mixture to roughly level it. Chill until hard, then cut into fingers.

    1. Bake Play Smile says:

      Yum sounds delicious!! You might find this website helpful for converting ingredients:

  17. Lily says:

    Hello hello – me again – how long will it last in the fridge???

    1. Lucy Mathieson says:

      Hi again! Up to 5 days 🙂

  18. John Malcon says:

    Hello, Lucy!
    Thank you for the perfect recipe! I sent to my wife a link on your blog!

    1. Lucy Mathieson says:

      Thank you!!!

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