Mars Bar cookies are SO easy to make and they’re so good that you’ll want to bake them over and over again. They’re soft and chewy, packed with tasty milk chocolate chips and gooey Mars Bar chunks.
After the huge success that was my Mars Bar traybake (and by that I mean I ate the whole pan in less than 2 days) and my Mars Bar brownies, I had the amazing idea to make these Mars Bar cookies.
They're the perfect mix of soft and chewy, and they're packed full of chocolate chunks and gooey caramel. I hope you enjoy them!
Ingredients
Here's what you'll need to make the best Mars Bar cookies:
- Butter: Using soft butter that's been cut into cubes will make mixing a lot easier. To soften your butter, you just need to leave it sitting out at room temperature for an hour or two before you start baking. It should feel soft but not wet or melted.
- Caster sugar: Caster sugar is a finer version of granulated white sugar and it gives the cookies a smoother texture. It's also known as superfine sugar in the US.
- Brown sugar: Use soft, light brown sugar for these cookies. Dark brown sugar has a super strong flavour that can be a little overpowering.
- Vanilla extract: I like to add this for extra flavour but you can skip it if you prefer. The Mars Bars and chocolate chips will give a lot of flavour anyway.
- Egg: You'll need 1 egg to bind the rest of the Mars Bar cookie dough ingredients together. I usually use medium-size eggs.
- Self-raising flour: I use self-raising flour in my cookies so that I don't need to add any extra baking soda or baking powder. Using this type of flour helps to create light, fluffy cookies with crispy edges.
- Chocolate chips: Although the Mars Bar adds a nice hit of chocolate, I wanted them to be really indulgent and flavourful, so I added a small handful of chocolate chips. I used milk chocolate chips but you can use any kind that you like.
- Mars bars: Of course, we need Mars Bars to make these cookies. I used 4 full-sized bars (51g each) and chopped them into small pieces. Alternatively, use 5 multipack bars (39.4g each) or 11 fun-size bars (18g each).
Equipment
- Mixing bowl: Use a large one because this recipe makes quite a lot of cookie dough.
- Electric whisk or stand mixer: Although this recipe can be done by hand, I like to use an electric whisk or stand mixer to help me mix the butter and sugar together. It'll save you from getting sore arms!
- Wooden spoon: To mix everything together. You can also use a rubber spatula.
- Baking trays: You can use one or two large baking trays for this recipe. These cookies spread a lot while they're baking so I recommend only baking 4-6 per tray. You can bake them in batches back to back using separate trays or wait for them to cool and reuse the same one.
- Baking or parchment paper: You'll need this if you're using traditional baking trays. If you're using a non-stick cookie tray then you can do without.
How to make Mars Bar cookies
Step 1: First start by preheating your oven. Preheat it to 180°C(350°F) or if you’re using a fan/convection oven, 160°C (325°F).
Step 2: Line two large baking trays with baking or parchment paper. If you only have one tray, don’t worry, you can bake your Mars Bar cookies in small batches and reuse the same one.
Step 3: Chop 4 full-sized Mars Bars (approximately 200g) into small chunks. Set aside for now.
Step 4: Add 150g of soft butter to a large bowl along with 130g of caster sugar and 100g of soft light brown sugar. Mix well using an electric whisk or stand mixer to help you. This step can be done by hand but it can be a little tricky.
Step 5: Next, add 1 egg to the bowl and 1 teaspoon of vanilla extract. Mix again until smooth.
Step 6: Now add 250g of self-raising flour to the mixture. Stir it in using a wooden spoon and when the mixture is starting to stick to itself, use your hands to press it into a big ball of cookie dough. If the dough is wet or sticky, add a little more flour. If it’s dry or crumbly, you can add a splash of milk.
Step 7: Add 50g of milk chocolate chips and the chopped Mars Bars. Gently knead them into the dough with your hands.
Step 8: Divide the Mars Bar cookie dough into 12 and roll each piece into a ball. Try to keep the Mars Bar chunks towards the centre of the balls rather than the edges. This will help prevent the caramel from spilling out and making the cookies lopsided.
Step 9: Place 4-6 cookies on each baking tray, leaving a couple of inches in between them to allow space for spreading. They’ll spread quite a lot as they bake!
Step 10: Bake your Mars Bar cookies for 11-12 minutes until they are very slightly golden brown at the edges. The key to a soft and chewy cookie is to underbake them slightly so although they’ll look pale and gooey, you need to resist the urge to keep baking them!
Step 11: Let your cookies cool completely before removing them from the tray. Then all that’s left to do is enjoy them!
Top Tips
- Try to keep the Mars Bar pieces away from the edges of the cookies before baking, which will help to prevent the caramel from spilling out and misshaping the cookies.
- Add a small chunk of Mars Bar onto the centre of a few cookies before baking for an extra touch of gooey caramel.
- If you prefer, you can use semi-sweet chocolate chips instead of milk chocolate chips. You can even use white chocolate chips if you really want to!
FAQ
If you keep them in an airtight container at room temperature, these cookies should taste good for at least 5 days.
Yes, Mars Bar cookies are the best for freezing. To freeze, pop them into airtight containers or wrap them tightly in clingfilm or tinfoil, and freeze for up to 1 month. When you’re ready to eat them, transfer them to a wire rack or plate and let them sit out at room temperature for an hour or so until fully thawed. I do not recommend refreezing these once they’ve been defrosted.
I hope you like these Mars Bar cookies. If you give them a go, please leave a review to let us know what you think. Enjoy!
More cookie recipes
BEST Mars Bar Cookies
Ingredients
- 150 g Butter softened at room temperature and cut into cubes (⅔ cup)
- 130 g Caster sugar (⅝ cups)
- 100 g Soft light brown sugar (½ cup)
- 1 Egg
- 1 Teaspoon Vanilla extract
- 250 g Self-raising flour (2 cups)
- 50 g Milk chocolate chips (∼2oz)
- 4 Full-sized Mars Bars chopped into small chunks (∼200g/7oz total)
Instructions
- Preheat your oven to 180°C (160°C for fan ovens). Line two large baking trays with baking paper.
- Using an electric whisk or stand mixer, mix the butter, caster sugar and brown sugar together in a large bowl. It should look like a thick paste.
- Next, add the egg and the vanilla extract and mix well until smooth.
- Add in all of the self-raising flour and mix it in. When it starts to stick together, use your hands to press the mixture into a ball of dough.
- Add the chocolate chips and chopped Mars Bars. Carefully knead them into the dough with your hands.
- Divide the dough into 12 equal-sized pieces and roll each piece into a ball. Try to ensure the Mars Bar pieces are more towards the centre of the balls rather than the edges. This will prevent caramel spilling out and burning.
- Place the dough balls on your lined tray(s), making sure to leave a couple of inches between each cookie to allow space for spreading. I recommend baking 4-6 per tray.
- Bake the cookies, one tray at a time, for 11-12 minutes. As soon as you see a slight golden brown colour at the edges, remove them from the oven. They'll still be pale and wobbly in the middle but will firm up as they cool. Don't keep baking them or they'll end up hard and crispy.
- Let the cookies cool completely before removing them from the tray.
Video
Notes
- If the dough is too sticky, you can add more flour. If it’s too dry, add a splash of milk to help it stick together.
- If caramel spills out of the sides while baking, you can use a large cookie cutter or spoon to gently shape the cookies back into circles while they’re still warm.
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