This simple recipe for Mars Bar Squares is made with just 4 simple ingredients, and is truly decadent! Also known as Mars Bar Slice, this easy dessert is perfect for any time of year.
Oh, and don't forget to check out my easy recipe for Mars Bar Cookies!
Mars Bar Squares are a delicious treat that is widely enjoyed throughout Canada and the UK.
Inspired by the popular candy bars, this sweet treat involves melting Mars Bars with butter, then folding in Rice Krispies, and topping it all with a creamy chocolate glaze. What's not to love!?
These are one of the first things I make when the holiday season rolls around, but you don't have to wait to make this no bake confection. It works for any occasion, and the leftovers freeze really well.
This is one of my most requested recipes when I bring it to gatherings, and for good reason: it tastes simply amazing!
Reasons to Love This Recipe:
- 4 Ingredients. Mars bars, chocolate chips, butter, and crispy rice cereal - that's all you need!
- Simple. No need to whip egg whites, fiddle with a candy thermometer or measure sticky golden syrup. Just melt, mix, and assemble.
- Great for the holiday season. Whether you love putting together cookie tins, or just serving up endless plates of sweet treats, these Mars Bar Squares are always a hit.
- Easy to make. Since this recipe can be made either on the stovetop or the microwave it's easy enough to make with kids. So if you want a project you can complete together, you're definitely going to want to try this recipe!
- Mars bars: You will need 4 regular-sized Mars chocolate bars, which are about 52 grams each. The size has changed over the years, but the recipe still works well with these new slightly smaller bars.
- Crisp rice cereal: Also known as Rice Krispies, these are added to the melted butter and Mars mixture to form the base.
- Butter: You can use salted or unsalted butter - totally your preference!
- Chocolate chips: I recommend using semi-sweet chocolate chips, but milk chocolate chips work well too.
Notes for the UK
Also known as Mars Bar Slice, this recipe features measurements in both imperial and metric. I weighed the ingredients myself, so you can be sure the weights are accurate - just toggle the recipe card to "metric".
Mars bars in the UK weigh 51 grams and 52 grams in Canada and the US, so there is no significant difference.
Check the recipe card for a full list of ingredients and the quantities needed.
- Baking pan: You will need an 8X8" (20.32 X 20.32 cm) square baking pan (AKA baking tin) for making this recipe. I highly recommend the USA Pan brand - they are sturdy, coated, and easy to clean.
- Parchment paper: My best tip for easy removal of the bars and practically effortless cleanup is parchment paper. Cut two pieces of parchment paper to the width of the pan, then crisscross them to fit. Fold the paper over the edges of the pan (or trim) and you're ready to go!
How to Make Mars Bar Squares
Step one: Add the butter and Mars bars to a microwave-safe bowl or a large saucepan.
Step two: Melt the butter and chocolate together using 30-second intervals in the microwave, or over medium to low heat on the stovetop.
Melt until everything combines easily when stirred.
Step three: Add the rice cereal and fold it into the mixture using a silicone spatula.
Step four: Press the cereal and melted chocolate mixture into the bottom of a parchment-lined 8X8" (20.3 X 20.3 cm) baking pan.
The Chocolate Topping
Step five: Add the chocolate chips and 3 tablespoons of butter to a heat proof bowl or a small saucepan.
Step six: Melt in 30-second intervals in the microwave, OR over low to medium heat on the stovetop. Stir well until the chocolate and butter melt together.
Step seven: Spread the melted chocolate on top of the rice cereal base, smoothing it into an even layer.
Step eight: Allow to cool at room temperature for 20-30 minutes, then score into bars (slice with a sharp knife where you want the bars to be).
Cover tightly with plastic wrap and chill in the refrigerator for 2-3 hours or until firm and set.
Step nine: Slice where you made the scoring marks previously, then serve and enjoy!
Storing Mars Bars Squares
- Transfer your leftover Mars Bar Squares to an airtight container.
- Place parchment or waxed paper between the layers to prevent sticking.
- Don't store at room temperature, instead store in the refrigerator to prevent the chocolate from melting.
- Your bars will keep in the fridge for up to 5 days.
- To freeze, wrap the bars individually before adding them to a plastic freezer bag. Label and freeze for up to 3 months.
Tips for Success
- Stovetop. When it comes to melting chocolate, using the stovetop method is going to give you the best results. The microwave works really well and is quick, but the stovetop method does a better job of melting chocolate. You will see better consistency and fewer cracks.
- Chopped Mars bars. If you really want the consistency to be good, go ahead and cut your Mars bars into small pieces. This helps them melt more evenly.
- Type of chocolate. For the chocolate topping use a good quality chocolate chip or baking chocolate. This will give you the best results. Melted milk chocolate tastes yummy, but it's not as smooth as standard semi-sweet chocolate.
Milky Way bar: If you can't find Mars, Milky Way is the closest substitute and should work well in this recipe. Swap them 1 for 1 in the recipe.
Snickers bars: These are similar to Mars bars, but they have some nuts, so the texture will be different. You can swap them 1 for 1 in the recipe.
If you loved this recipe for Mars Bar Squares, let me know by leaving a 5-star review in the recipe card, OR tag me on Instagram @maritimecountrykitchen!
Mars Bar Squares
- 4 Mars bars 52 grams each
- ½ cup butter
- 3 cups crispy rice cereal (Rice Krispies)
- 1 cup chocolate chips
- 3 tablespoons butter
- Line an 8X8 baking pan with overlapping pieces of parchment paper, or spray lightly with cooking spray.
- Unwrap the Mars bars and cut them into small pieces. Place them in a microwave-safe bowl along with ½ cup of butter.
- Heat in the microwave for 1 minute, then stir well to combine. If the chocolate bars are not completely melted heat for an additional 30 seconds. Stir until the butter and chocolate mix together easily.
- Add 3 cups of crisp rice cereal to the bowl and fold it in using a silicone spatula. Continue to mix it until the cereal is coated with the melted chocolate mixture.
- Transfer the cereal mixture to the prepared baking pan, pressing it into the pan in an even layer.
- Add 1 cup of chocolate chips and 3 tablespoons of butter to a microwave-safe bowl and heat in 30-second intervals - stirring after each one - until the chocolate and butter are completely melted together. This shouldn’t take any longer than 1-2 minutes total.
- Spread the melted chocolate on top of the cereal layer in an even layer.
- Allow the squares to cool at room temperature for about 20-30 minutes, then score into the desired amount of bars.
- Cover with plastic wrap and place in the fridge to chill for 2-3 hours, or until set.
- Run a knife through the scored lines, cutting them into bars. Serve and enjoy!