Mars Bar Slice

This chewy, chocolate Mars Bar Slice Recipe is one of the best things to come out of the 1980s. It's a no-bake recipe and is so easy and simple. The only challenge is to stop eating after one slice!

Jump to:

• The best recipe around
• Ingredient notes
• How to make Mars Bar Slice
• Top tips
• Variation ideas
• Storage
• Mars Bar Slice FAQs
• More sensational slice recipes
• Mars Bar Slice

The best recipe around

There are so many slight variations of this recipe. But I'm here to convince you that this one is the ultimate Mars Bar Slice recipe:

• I've done my research! This recipe has been adapted from the recipe my mum used when I was a kid and others I've tried since then. And I've tried more than a few!
• This version is the perfect balance of crunchy and chewy
• It won't crumble – something that might disappoint a true Mars Bar Slice connoisseur.
• It'll look as good as it tastes – nice and neat just like the picture above – if you follow the instructions below.

Ready? Just gather the 5 ingredients and you'll have it ready in 20 minutes flat.

Ingredient notes

To make this recipe, you'll need:

• Mars Bars (4 and a half of them these days – they've shrunk a little over the years!)
• Rice Bubbles (you might call them Rice Krispies or Ricies if you're not from the land down under)
• butter (the regular salted variety)
• golden syrup (you can substitute agave nectar, cane syrup or brown rice syrup)
• milk chocolate (use good quality chocolate rather than cooking chocolate – I'm a fan of Cadbury).

The ingredient list and measurements can be found in the recipe card at the bottom of the post.

Equipment

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.

How to make Mars Bar Slice

Start by greasing and lining the slice tin, leave some baking paper overhanging on each side so you can gently ease the slice from the tin to cut it up (see image 1). 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!

Next, measure out the rice bubbles into a large mixing bowl (see image 2).

Break up the mars bars into pieces and place into a saucepan along with the butter and syrup (see image 3).

Heat the ingredients in the saucepan gently over low heat until they're melted (see image 4) and keep stirring until the mixture reaches a smooth, runny consistency (see image 5).

TIP: I swap the spoon for a small whisk towards the end of the process to get a super smooth consistency. Pour this mixture into the bowl with the rice bubbles and stir quickly to combine (see image 6).

Pour the mixture into the prepared slice tin and then use the back of a spoon to push it firmly into the tin. Smooth the top out evenly by running the back of the spoon back and forth along the surface (see image 7).

TIP: Make sure you press the mixture firmly into the tin to avoid crumbly slice.

Next, break up the chocolate and place it into a microwave-proof bowl. 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 (see image 8).

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. Alternatively, use a spoon to spread the melted chocolate over the top.

Next, it's into the fridge to set. Be patient! It won't be long and you'll be enjoying a slice or two.

When the slice has set (it'll take a few hours) and you're ready to cut it into squares, take the slice out of the fridge and leave it for about 20 minutes.

TIP: If you try to cut it up straight from the fridge the top chocolate layer may crack. Some people add a teaspoon of oil to the chocolate to prevent this, but I prefer to just let it soften a little.

Ease the slice, whole, from the tray using the overhanging baking paper and then cut into squares using a large, sharp knife.

Top tips

While it's a fairly straightforward process, keep these four tips in mind to totally nail this recipe:

• use good quality, fresh ingredients
• when melting the butter, golden syrup and Mars Bars together, the mixture can tend to be clumpy – make sure you use a whisk to stir it towards the end of the melting process and get a super smooth result every time
• remember to use the back of a metal spoon to flatten the slice evenly on top and ensure it's pressed firmly into the tin
• avoid cracking the top chocolate layer by allowing the slice some time at room temperature before cutting into squares.

Variation ideas

The original recipe is really hard to improve upon, it's just so good as it is. However, some people like to add mini marshmallows, Maltesers, 100s & 1000s or M&Ms to the mix. Stir these into 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.

At Christmas, you can also go a little fancy and make Mars Bar Slice Christmas Puddings.

Instead of pressing the slice into a tin, wait until the mixture can be handled and then roll into balls. Place into fridge and melt 180 grams milk chocolate and 60 grams milk chocolate. Pour the melted milk chocolate over the balls and then a little of the white chocolate and decorate with Christmas M&Ms.

Storage

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. 

It will last at least a couple of weeks stored in an airtight container in the fridge.

Mars Bar Slice FAQs

More sensational slice recipes

There are so many wonderful recipes in the slice collection. Here are four of my favourites:

Made this recipe and love it? Please take a moment to rate the recipe and leave a comment below. It’s such a help to others who want to try the recipe. (And it really makes my day to hear how Nana Ling's recipes are being made, shared and loved all around the world! - Libby x)

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