How to Make Easy Peasy Mars Bar Slice

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If you love Mars Bars, you’ll LOVE this easy Mars Bar Slice recipe! A no bake treat filled with a crunchy yet chewy texture, and ALL the Mars Bar flavour you could wish for. Keep reading to learn just how easy it is to make!

Why you’ll love this recipe

My brother is a HUGE Mars Bar fan. If there’s a Mars Bar treat to be made, you name it, I’ve made it! Along with Mars Bar cupcakes, this Mars Bar Slice recipe is one of his favourites. Filled with crunchy rice cereal, and little pockets of caramel and nougat – topped off with yet more chocolate… It’s easy to understand why!!

Ingredients

Confused about what ingredients to buy? Not sure about a substitution? Here’s everything you might need to know…

Mars Bars – It would still taste great with cheaper alternatives, but if you’re making this for a true Mars Bar fan, get the original. (Just look out for offers!)
Butter – Unsalted, salted, it doesn’t really matter. It’s merely a vessel for the melted Mars Bars!
Golden Syrup – Don’t skip this if you can help it. It adds a lovely caramel flavour!
Puffed Rice Cereal – I used Rice Krispies, but they can be expensive if not on offer. Any brand will work just as well!
Milk Chocolate – Use your favourite, or whatever you already have. Galaxy works well, as it’s the same chocolate used in Mars Bars.
Blonde Chocolate – This is entirely optional. I used Caramac bars, but any blonde or even white chocolate would look and taste great.

Five bars of Mars Bar Slice on a wooden board.

Emma’s top tips

Here are tips you’ll find helpful when making this recipe.

Take your time melting the Mars Bars. It doesn’t matter if they don’t fully melt, but you risk burning things if your temperature is too high.
For the milk chocolate topping, I recommend using Galaxy chocolate. This makes the whole thing taste even more like Mars Bars!
If you’re short on time, you can set your Mars Bar Slice in the fridge. Just be aware that the chocolate may not have that nice snap as a result (due to the dramatic temperature change).

Timings

Have limited time? Struggle with recipe timings? Or juggling around other things? Here’s some time managing info to make your life easier!

It will take around 5-10 minutes to melt the Mars bars.
Making the rice cereal mixture will take less than 5 minutes.
Pressing the mixture into the tin should take no more than 3 mins.
The chocolate topping will take about 5 mins.
The optional decoration will only take 2-3 minutes.

Several slices of Mars Bar slice on a wooden chopping board.

Mars Bar Slice – Step by Step Picture Recipe

(For a printer friendly version, see the recipe card at the end of this post)

Ingredients

Here is what you will need to make 9 Large Bars or 16 Smaller Bars.

Please note, this recipe includes both UK metric and US Cup measurements.

4 x 39g (1.4 oz) Mars Bars
75g (1/3 Cup) Unsalted Butter
1 tsp Golden Syrup
75g (3 Cups) Rice Krispies
200g (7 oz) Milk Chocolate
60g (2.1 oz) Blonde Chocolate, optional

Essential Equipment

20cm (8″) Square Baking Tin
Chopping Board
Sharp Knife
Saucepan
Wooden Spoon
2 x Large Mixing Bowls
Spatula
Piping Bag (or plastic food bag), optional
Skewer (or knife), optional

Instructions

First, very lightly grease (just enough so the paper will stick) and line the baking tin with baking paper and set to one side.

Roughly chop two and a half Mars Bars and place them into a small saucepan. Then chop the remaining one and a half into small chunks, and set those aside for later.

Add the butter (75g | 1/3 Cup) and golden syrup (1 tsp) to the saucepan, then set it over a low heat. Gently melt the contents, stirring constantly with a wooden spoon.

Mars Bars, butter and golden syrup melting in a saucepan.

Don’t worry if all the nougat doesn’t melt. Just make sure you allow it to cool for a few minutes.

Next, tip the Rice Krispies (75g | 3 Cups) and the pieces of Mars Bar you set aside earlier, into a large bowl. Pour the melted mixture over and stir thoroughly.

Rice Krispies cereal mixed with melted mars bars in a large mixing bowl.

Now press the mixture firmly into the prepared tin, and place it into the fridge to chill while we prepare the chocolate topping.

Mars Bar and Rice Krispie mixture pressed into a lined square baking tin.

Break the milk chocolate (200g | 7 oz) into a large glass bowl. Then heat it in the microwave in 10 second intervals. When it’s two thirds melted, stop heating and stir continuously until it’s fully melted.

Finally, smooth the melted chocolate over the top of the chilled Mars Bar Rice Krispie mixture.

Melted milk chocolate smoothed over the top of a melted Mars Bar and Rice Krispie mixture in a square baking tin.

Optional decoration

NOTE you need to act fairly quickly. If the milk chocolate has started to set before you add the blonde chocolate, the feathering technique won’t work.

If you are going to decorate the top with blonde chocolate (60g | 2.1 oz), break it into a piping bag. Then heat in 10 second intervals in the microwave, giving it a good squish after each time. Keep going until fully melted.

Melted blonde chocolate in a plastic zip lock bag.

Then snip the end off the piping bag, and pipe lines across the top of the Mars Bar Slice.

Melted blonde chocolate piped in lines on top of the milk chocolate topping.

Now take a skewer (or knife) and drag lines up and down, in the opposite direction that you piped the first lines.

Melted blonde chocolate being feathered on top of the melted milk chocolate.

This should create a feathered look. You can now leave your Mars Bar Slice to set at room temperature.

Melted Milk chocolate topping with blonde chocolate feathering on top.

How to slice and store Mars Bar Slice

As this can be quite sticky, it’s easiest to cut using a warm knife. To do this, simply run a sharp knife under a hot tap, and wipe dry before you slice. Cut into 9 or 16 pieces, depending on your preference.

Store your Mars Bar Slice in an airtight container in the fridge, and consume within 5 days.

Mars Bar Slice bars on a wooden board, with a glass of milk to the side.

FAQs

Can you melt Mars Bars?

Yes! So long as you melt it gently, you can melt Mars Bars. The nougat may not fully melt, but in this recipe that doesn’t really matter.

Do you have to use Rice Krispies?

No, you don’t have to use Rice Krispies. Any brand of puffed rice cereal will work, it doesn’t need to be expensive.

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Two Mars Bar Slices on a wooden board. A text overlay says "Easy no bake Mars Bar slice recipe".