Mars Bar Brownies!

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Easy and Fudgey Mars Bar Brownies! So Chocolatey, So Delicious!

It’s the time to have something so chocolatey, that you’ll want to make them again and again. These Mars Bar Brownies is exactly that. So unbelievably chocolatey and Fudgey they are on a next level. Are you intrigued yet?

Anyway. I thought I would start this recipe post off with a statement that makes you go these MUST be good, and then you’ll see the pictures and be like oh heyyy look at them, yes, they are amazing. And I really hope you guys did because I certainly did. 

From the beginning I must say that Mars Bars in the UK, are Milkyway bars in the US, so if some of my American readers are a little confused right now, just roll with a Milkyway instead. I finally found out why there is a different in name the other day (due to a family spat back in the day), and I was surprised that that was all it was. 

Even so, Mars Bars are the one. They are slightly underrated in my opinion, but I do adore them. For those who have never experienced the wonder that is a Mars Bar… they are Nougat and Caramel, coated in Milk Chocolate. They are delightful. 

When I was thinking about what chocolate bars I should bake with, I wanted to use one I hadn’t tried in a while. I’ve used Mars Bars four times on this blog already, my favourite time being my Mars Bar Cheesecake, but it was so long ago! 

These brownies came about because of my craving for something Mars Bar, and also because they were on offer in the supermarket I was in at the time so that made the bake cheaper. Always handy in my books. I couldn’t resist! 

I went for a classic style brownie, that I have used in so many recipe posts now. And I will say it time and time again, PLEASE USE DARK CHOCOLATE IN THE BROWNIE MIXTURE. I don’t really care if you ‘don’t like dark chocolate’ it will make such a good brownie, and not too ‘dark’ a flavour, so PLEASE stick with it. 

If you use milk chocolate, the mixture is so much thinner, and when people moan to me that their brownies didn’t bake properly, and say they switched to milk chocolate then that is why. It doesn’t work the same, and doesn’t make them nearly as fudgey. Dark chocolate is the best. 

The key really is to make the brownie mixture as thick as possible, and dollop on all your Brownie bits. When the caramel and nougat bakes, it’ll make little pockets of deliciousness for you to enjoy, and they are just a combination to behold. SO tasty!

I realise its a faff, but freezing the Mars Bar bits before baking really is the best practice so they don’t explode everywhere completely and utterly, but its not completely essential. However, if you can, I would 100% recommend it! 

These brownies are so fudgey, so moreish, and delightful. I really hope they live up to your expectations for my latest Mars Bar creation! Enjoy! X

5 from 7 votes
Mars Bar Brownies
Mars Bar Brownies!
Prep Time
15 mins
Cook Time
25 mins
Cooling Time
1 hr
Total Time
1 hr 35 mins

Easy and Fudgey Mars Bar Brownies! So Chocolatey, So Delicious!

Course: Traybakes
Cuisine: Brownies
Keyword: Mars Bar
Servings: 16 Pieces
Calories: 392 kcal
Author: Jane's Patisserie
  • 200 g Dark Chocolate
  • 200 g Unsalted Butter
  • 3 Large Eggs (or 4 medium)
  • 275 g Light Brown Sugar
  • 100 g Plain Flour
  • 50 g Cocoa Powder
  • 300 g Mars Bar (chopped & frozen)
  • 100 g Milk Chocolate Chips (optional)
Optional Decoration
  • 50 g Milk Chocolate Melted
  • Mars Bar Pieces
  1. Preheat your oven to 180C/160C Fan and line a 9x9" baking tin with parchment paper!

  2. Melt together your Dark Chocolate and Unsalted Butter until smooth in the microwave or in a bowl over a pan of simmering water. Leave to cool for a few minutes

  3. Using an electric whisk/stand mixer, whisk your Eggs and Sugar together for 5 minutes or so on high speed, or until the mixture has doubled in volume, is alot paler, and leaves a trail for a few seconds when you lift the whisk out.

  4. Pour in the chocolate/butter mix and fold through very carefully.

  5. Add in the Flour and Cocoa Powder and fold through carefully again.

  6. Add in your frozen chunks of Mars Bar and chocolate chips and fold in. Pour the mixture into the tin and bake in the oven for 25-30+ minutes.

  7. Leave to cool in the tin, and then enjoy!

  8. To decorate your brownies if you fancy it... melt your chocolate and drizzle over the brownies, and add pieces of Mars Bar to each one! Set in the fridge, then chop up and enjoy!

Recipe Notes
  • Please try and freeze the Mars Bar first as it'll work so much better!
  • These will last for one week+!
  • You can use caster sugar instead of the brown sugar, the brown sugar just works really well for the Mars Bar theme!
  • If your brownies are taking much longer than stated to bake, your oven may have been the wrong temperature, or you over mixed your batter. Keep adding on 5 minutes till they're done and cover with foil if need be!
Nutrition Facts
Mars Bar Brownies!
Amount Per Serving
Calories 392 Calories from Fat 198
% Daily Value*
Fat 22g34%
Saturated Fat 13g81%
Cholesterol 69mg23%
Sodium 60mg3%
Potassium 207mg6%
Carbohydrates 47g16%
Fiber 3g13%
Sugar 35g39%
Protein 5g10%
Vitamin A 410IU8%
Vitamin C 0.2mg0%
Calcium 66mg7%
Iron 2.7mg15%
* Percent Daily Values are based on a 2000 calorie diet.


Find my other Recipes on my Recipes Page!

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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. 5 stars
    These look amazing! When you mention dark choc – should this be cooking / non-cooking and should it be maximum darkness for maximum fudginess? I love fudgy but loathe gooey brownies 🙂

  2. Hi Jane ! I made these last night they look amazing ! Very gooey in the middle I should have maybe cooked a little longer but I personally like mine gooey ! Just a storage question really are they best kept in the fridge ? Or just in airtight container at room temp ?
    Thanks so much for all your recipes baking them really helps me relax.

  3. Hi Jane, I just tried making these and despite following the recipe completely, I have just cut them and they are still almost raw in the middle. What could I be doing wrong? I baked for 30 mins.

    1. As mentioned in the post, they can take longer in some ovens. Also, if they’re not whisked enough at the beginning, or mixed too harshly in the folding stage etc. It’s near impossible to say!

  4. 5 stars
    Absolutely love these brownies! Made them last week for the first time for my Macmillan coffee morning and they were enjoyed by everyone! Making them again today as I didn’t get a piece..haha. Can’t wait! Totally indulgent. Many thanks Jane!

  5. Hi Jane,
    I’ve made these a few time and the barsbar inside just melts but I think I know why .. is it because I’m freezing the mars bar first then cutting it and it’s just basically disintegrating lol ? Should I pre cut them and then freeze them ?

    1. Hiya! Chances are you are cutting them too small – as you can see from the images, mine are definitely still there! I typically cut mine and freeze anyway, but it shouldn’t make a difference doing it the other way around – frozen is frozen!

  6. 5 stars
    This is a great recipe, but despite freezing my Mars Bars overnight, they still melted entirely and left Mars-Bar-chunk-shaped holes. Not an issue for me, they still tasted absolutely delicious and the nougat stayed solid.

  7. 5 stars
    Hi Jane! These look amazing and I’m going to make them tonight! How long should I freeze the mars bars for? Thanks x

  8. Hi Jane
    Im making these today and also making your choc fudge cake, is it ok to use 74 percent cocoa dark chocolate in both these recipes or should i use a higher percentage dark chocolate ? Many thanks Doreen

  9. Just taken out of oven your terry’s choc orange brownies, i did find i had to bake it extra 10 mins and although it still looked a little wobbly in the centre i think its firming up as it cools, cant wait to taste them then will definatly have a go at these mars brownies, thank you your recipes are so easy to follow xxx

  10. Hi Jane,
    I’ve noticed you’ve swapped to using light brown sugar instead of caster sugar in your latest brownie recipes – is there a reason for this? Do you find light brown sugar makes better brownies? Just wondering if I should start using that instead of caster sugar for your older brownie recipes.

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