Super easy M&M cookie bars are thick and chewy, and loaded with M&Ms and chocolate chunks. These cookie bars are all the taste and texture of a cookie, but baked into a bar!

Hi hi! I am just jumping in to share the recipe for these M&M Cookie bars! This easy cookie bar recipe is a twist on my regular M&M cookies, with a few tweaks made, and baked into thick and chewy M&M cookie bars rather than individual cookies.
I love making homemade cookies, especially my perfect chocolate chip cookie recipe, but sometimes you don't want to put in all the effort it takes to make cookies from scratch, but you still need to scratch that cookie itch. This is where these M&M cookie bars come in. They have all the taste and texture of an M&M cookie, but you spread the batter into a pan and the whole thing goes in the oven. No chilling required - easy M&M cookie bars in under an hour.
If you love cookie bars make sure to also check out my chocolate chip cookie bars recipe, and my brookies recipe!
How to make M&M Cookie bars
These M&M cookie bars are super easy to put together. They are made with an egg yolk cookie base, which I use in my M&M cookies and my egg yolk chocolate chip cookies. Using egg yolk gives the cookies a super chewy finish, and is a great way to use up extra yolks you may have on hand. I have a bunch of egg yolk recipes on my site if you need any extra inspiration!
- Whip together wet ingredients. This recipe uses melted butter, so there is no need to wait for butter to come to room temperature. Combine with the brown sugar, granulated sugar, yolks, and vanilla in a large bowl. Whip until thick and lightened in colour - this step will give you that nice crinkly finish on your cookie bars.
- Add dry ingredients. Add the flour, baking powder and salt and mix to combine - don't mix too far at this point to avoid over mixing.
- Add mix-ins. Add the chocolate and M&M candies, and stir to incorporate. I like to do this part by hand to make sure most of the M&Ms stay intact. I use chopped chocolate, but you can use chocolate chips if you like too!
- Press the dough into the pan. I use an 8" pan, lined with parchment paper to ensure that the cookie bars are easy to remove afterward. Press the dough into the pan, flattening down with a spatula, then using an offset spatula if you want it super smooth.
- Bake. Bake the M&M cookie bars for 20 to 22 minutes until perfectly golden brown, then remove from the oven and leave to cool in the pan before slicing and enjoying.
Can cookie bars be made ahead of time?
These M&M cookie bars are great to make ahead of time - you can make them a day or two ahead, and store in an airtight container at room temperature until you are ready to serve. They keep for four to five days at room temperature.
If you would like to freeze them, layer them in an airtight container with parchment paper between the layers, then freeze. Defrost at room temperature or in the fridge - defrosted cookies often benefit from a quick zap in the microwave to refresh before eating!
If you would like to make the cookie dough ahead of time, you can press it into the baking pan, cover in plastic wrap, then place the whole thing into the fridge and bake from chilled, for warm M&M cookie bars on hand for an easy dessert!
How to cut cookie bars
I get asked this question often - how do you get a clean cut on your cookie bars and brownies? There are a few wee tips for getting a nice clean cut:
- Use a sharp knife. This makes a huge difference. Using a really sharp knife for cutting things gives you a nice clean cut.
- Wipe the blade between cuts. Having a clean blade between cuts means that you reduce the chance of crumbs.
- Let the cookie bars cool. If you can't wait, then just go for it, it all ends up mixed up in your tummy. But if you would like a super clean cut on these M&M cookie bars, leave them to cool first before removing from the pan and slicing.
A few more tips for cookie bars:
- Don't overbake them. If you over bake your cookie bars, they will be slightly dry around the outside. You are better off erring on the side of underbaked and they finish off baking when you remove them from the oven.
- To test for doneness, you can insert a toothpick into the middle of your bars - it should come out with a few crumbs. Otherwise I like to do it by touch and sight - you want to look for the edges to be puffed up slightly and the top of the bars to be set.
- If you want that slightly crinkly top on your M&M cookie bars, make sure that you whip the butter, sugar and egg yolks together well in the first step. Having room temperature eggs will mean that they whip up nicely too.
Frequently Asked Questions
What tools and equipment do you use?
You can find a full list of the tools and equipment I use on my products page
Can I add other mix-ins?
Add whatever you like! These M&M bars would be great with nuts such as walnuts or peanuts added (toast them first), or you can use different kinds of M&M candy (the peanut butter ones would be amazing) or add in some white chocolate chips. You can also mix up the kind of chocolate you use - I used dark chocolate but milk chocolate would be delicious too.
Can I make this recipe in a stand mixer?
Yes you can, but I find it just as easy to use a large bowl and a whisk! You can also use an electric hand mixer.
For more cookie and bar recipes, check out:
❤️ Made this recipe and love it? ❤️
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Answers to your baking questions
Over the years, many of you have asked me questions about:
- baking in grams
- adjusting oven temperatures
- what kind of salt to use
- and many more!
I've curated and answered them all for your easy reference in this frequently asked questions post!
30 Minute M&M Cookie Bars
- Prep Time: 10 minutes
- Cook Time: 25 minutes
- Total Time: 35 minutes
- Yield: 12 servings 1x
- Category: Cookies
- Method: Baking
- Cuisine: American
Description
Super easy M&M cookie bars are thick and chewy, and loaded with M&Ms and chocolate chunks. These cookie bars are all the taste and texture of a cookie, but baked into a bar!
Ingredients
- 100g unsalted butter, melted and cooled (re-weigh after melting and add a little extra butter if needed)
- 120g light or dark brown sugar
- 45g granulated sugar
- 2 large egg yolks, at room temperature (about 45g egg yolks)
- 1 tsp vanilla bean paste or vanilla extract
- 135g all-purpose flour
- ¼ tsp baking powder
- 2g salt (½ tsp kosher salt)
- 180g m&ms plus a few more for the tops, optional
- 85g dark chocolate, chopped
Instructions
- Preheat the oven to 350°f / 180°c. Grease and line an 8" (20cm) non stick baking pan, leaving the parchment extending over the sides to form a sling. Secure with binder clips if desired.
- In a medium bowl, combine the melted butter, brown sugar, granulated sugar, egg yolks, and vanilla. Whip well with a whisk or a handheld electric mixer until the mixture has thickened and lightened in colour slightly.
- Add the flour, baking powder and salt, and mix to combine with a spatula until just a few streaks remain.
- Add in the m&ms and chopped chocolate and mix to incorporate with a spatula.
- Press the dough into the prepared pan, smoothing down with an offset spatula. Add a few extra m&ms to the top of the cookie if desired.
- Bake the cookie bars for 20 to 22 minutes, until the top of the cookie is golden brown and set and the edges have started to firm up slightly. If you would like the edges of your cookie bar to be crispy, bake for a little longer.
- Remove the cookie bars from the oven and leave to cool in the pan on a wire rack. Remove from the pan using the parchment paper sling. Cut into pieces using a sharp knife.
- Store cookie bars in an airtight container at room temperature for up to 3 days.
Keywords: Cookie bars, m&m cookies, m&m cookie bars
Comments
So good!!!!
★★★★★
These come together so quickly. Thank you for this recipe!,
★★★★★
This recipe is very simple and so quick to make - the bars turned out so well! Will definitely make again. Mine did turn out a bit saltier than I expected (not the worst thing!), which we are warned about in the notes re saltier salt, so definitely pay attention to the type of salt you are using.
★★★★★
I love that Erin provides the weight of the ingredients. I followed the recipe as written, preparing the butter and letting the yolks come to room temperature. I will make this recipe again ) & again)
★★★★★
Nice simple recipe, and they turned out perfectly! A hit with everyone in the house, will be a lovely lunchbox treat this week. This recipe is definitely a keeper!
★★★★★
I am an absolute novice baker, in fact I would call myself a pretty terrible baker. But I just made these are they turned out perfectly! My family are loving them. Thank you!
★★★★★
I made these cookie bars on Halloween and brought them to my brothers house. I topped them with the “shitty” chocolate frosting and they were a huge hit! I only had mini m&m’s not regular but they were still awesome. I love making cookies but there’s just something so simple and so much better about a cookie in bar form. My husband asked me to make them again today, 3 days after Halloween! The frosting was simple and so good. It came together in minutes. I had exactly 20g of cocoa left in my pantry so it really worked out. I will for sure be making the bars and frosting again very soon!
★★★★★
I've made these three times and every time they are consistent and amazing!
★★★★★
These are my new favorite, and not just because I overbought red and green M&Ms in December and will be using them well into March. Even my husband, who prefers raw cookie dough and says he is “not a bar person” (what? who is not a bar person?), devoured these. So chewy, butterscotchy, and easy (+ fast) when you need a cookie fix. Thank you, Erin!
★★★★★
Wanted something quick to make and tasty and this recipe did not disappoint! Thank you!
★★★★★
Quick and easy to make when you’re craving cookies but don’t want to spend the day scooping dough and baking in batches.
★★★★★