These extra soft and chewy M&M cookie bars are so easy to make—no mixer, no dough chilling, no individual dough rolling required! You can use a mix of regular and mini M&Ms and chocolate chips for texture variety, and change out the colors to make them festive for a holiday.
One reader, Donna, commented: “I made these bars today and I love how quick and easy they are to make. I decided somewhat impulsively to bake and was pleased to find this recipe which calls for melted rather than room temperature butter, and I didn’t need to use the mixer either! These cookies are absolutely delicious and soft and chewy on the inside. ★★★★★“
Finally a cookie recipe without chilling!
Let’s call these no-chill, no-roll M&M cookies! When you need a big batch of cookies but are pressed for time (or mental energy, LOL), cookie bars are the solution. This recipe makes a generously sized 9×13-inch pan of M&M cookie bars, perfect for sharing, especially at the holidays. Kids love these, but so do adults. Seriously, aside from special diets, have you ever met anyone who would turn down a chewy chocolate chip M&M cookie bar? I’m pretty sure I haven’t!
Here’s Why You’ll Love These M&M Cookie Bars
- Like a bigger batch of soft chocolate chip cookie bars—with colorful M&M candies!
- Makes a large pan to serve a crowd.
- A great recipe for young bakers to help with.
- No mixer, no dough chilling, no dough ball rolling—a no fuss dessert recipe!
- Soft in the center, crisp around the edges.
- As easy as a box mix, but way more delicious.
- Add chocolate chips or white chocolate chips for texture variety.
- Choose your color M&Ms to match a holiday or theme.
Unlike these soft-baked M&M cookies, there’s no dough chilling or rolling dough into individual balls and baking in batches. The only waiting you’ll have to suffer through is for the pan to cool for 1 hour before you cut them into bars. (I know, I’m sorry.)
Easy Ingredients, No Mixer
Like with these favorite chewy chocolate chip cookies, using melted butter makes for the softest, chewiest bar cookies. I usually like to use melted butter in bar recipes like brownies and blondies because the bars taste chewy, not cakey. I tested this recipe with creamed softened butter, and the baked result ended up looking more like a puffy sheet cake.
Using melted butter also means you don’t need an electric mixer to make these bar cookies, AND you get that shiny, crackled look on top similar to brownies.
This recipe is similar to the Super Chewy Chocolate Chip Cookie Bars on page 28 of Sally’s Cookie Addiction, but I reduced the sugar a bit, since M&Ms are so sweet. We’re doing away with the extra egg yolk, and instead ensuring softness with an extra 1/2 teaspoon of cornstarch.
It’s also similar to my smaller recipe for chocolate chip cookie bars, but scaled up to make a full 9×13-inch pan. Here’s everything you need:
- Flour: All-purpose flour is the base of this recipe.
- Baking Soda: Baking soda helps these bars rise as they bake.
- Cornstarch: Cornstarch gives the cookie bars that ultra-soft consistency we all know and love.
- Salt: Salt adds flavor and balances the sweetness.
- Butter: Use melted butter in this recipe for the chewiest cookie bars. Because we use melted butter, there’s no need to get out your mixer.
- Sugar: I like to use a mix of brown sugar and white granulated sugar this recipe. More brown sugar than white granulated sugar promises an extra soft and chewy cookie bar because there’s more moisture in brown sugar.
- Eggs: Eggs bind everything together and add richness.
- Vanilla Extract: Pure vanilla extract adds flavor. If you have any homemade vanilla extract, use that!
- M&M Candies: Use regular-size, mini, or a mix of both. I also like to crush up about 1/4 cup of the M&Ms so some are broken, and sprinkle some on top. Totally optional—just adds some texture variety. You can even use different colors for different holidays. I love using red, white, and blue M&Ms for one of my 4th of July desserts.
- Chocolate Chips: I typically use semi-sweet chocolate chips, but feel free to swap them for white chocolate chips, peanut butter chips, or butterscotch chips.
Have I Mentioned No Dough Chilling?
Just melt, mix, press, and bake! Chant it in your head while you get out the ingredients. Melt, mix, press, bake! Melt, mix, press, bake! No dough chill! No dough chill!
The dough will be slick from the melted butter, but should be easy enough to spread/press into the pan. In fact, it doesn’t even look like regular cookie dough and you might remember that from a batch of these chewy chocolate chip cookies. Before & after adding your add-ins:
I strongly recommend lining the baking pan with parchment paper (with overhang on the sides) to make cutting into bars easier. Spread the dough into the pan:
It’s almost gooey-like, so it’s easier to spread than regular, creamy-thick cookie dough. Bake for just 26–30 minutes and avoid over-baking:
I press a few more M&Ms and chocolate chips into the tops of the warm cookie bars, for looks. This is optional. Cool the bars for 1 hour inside the pan, then simply lift the whole thing out using the parchment paper lining. Set it onto a cutting board and slice. They’ll still be a bit warm and that’s fine!
Success Tips for M&M Cookie Bars
- Line the pan so you can easily remove the bars as a whole and slice them, just like I recommend when making rice krispie treats and homemade brownies, too.
- Don’t over-bake. Check the bars around 24 minutes into baking, and if you notice they’re browning too much, tent foil over the pan for the remaining bake time.
- Wait at least 1 hour to slice, for neat slices.
Can I Make These With Brown Butter?
Yes! If you want to amp up the depth of flavor by using browned butter, you absolutely can! My team and I have tested it, and you need to start with an extra 3 Tablespoons of butter to make up for the moisture loss that occurs during browning. Otherwise, the bars will taste dry.
Feel Free to Pipe Some Buttercream Decor
These M&M cookie bars are fabulous on their own, but then again, a little frosting is always a good idea. My favorite chocolate buttercream is far from basic; it’s incredibly silky, smooth, and rich. Even though it’s wonderfully creamy, it holds its shape well, and is perfect for piping. It makes a delicious and beautiful finishing touch on this chocolate chip cookie cake, and would have the same effect on these cookie bars if you want to add some flair!
This recipe is part of my annual cookie countdown called Sally’s Cookie Palooza. It’s the biggest, most delicious event of the year! Browse dozens of cookie recipes over on the Sally’s Cookie Palooza page.
Soft M&M Cookie Bars
- Prep Time: 15 minutes
- Cook Time: 27 minutes
- Total Time: 1 hour, 40 minutes (includes slight cooling)
- Yield: 24 bars
- Category: Dessert
- Method: Baking
- Cuisine: American
Description
Think of these bars as no-chilling, no-rolling EASY M&M cookies! Using melted butter, more brown sugar than white sugar, and a touch of cornstarch guarantee the absolute softest, chewiest M&M cookie bar texture.
Ingredients
- 2 and 3/4 cups (343g) all-purpose flour (spooned and leveled)
- 1 and 1/2 teaspoons cornstarch
- 1 teaspoon baking soda
- 1/2 teaspoon salt
- 1 cup (16 Tbsp; 226g) unsalted butter, melted & cooled for just 5 minutes*
- 1 cup (200g) packed light or dark brown sugar
- 1/2 cup (100g) granulated sugar
- 2 large eggs, at room temperature
- 2 teaspoons pure vanilla extract
- 1 and 1/4 cups (about 260g) mini or regular-size M&Ms
- 3/4 cup (135) semi-sweet chocolate chips
Instructions
- Preheat the oven to 350°F (177°C). Adjust oven rack to the center rack position. Line the bottom and sides of a 9×13-inch metal or glass baking pan with parchment paper, leaving an overhang on the sides to easily lift the bars out of the pan. Set aside.
- Whisk the flour, cornstarch, baking soda, and salt together in a large bowl. Set aside.
- In a medium bowl, whisk the melted butter, brown sugar, and granulated sugar together until no brown sugar lumps remain. Whisk in the eggs and vanilla extract. Pour this into the flour mixture and mix together with a large spoon or silicone spatula. The dough will be very soft, slick, and thick. Fold in the M&Ms and chocolate chips. The M&Ms and chips may not stick to the dough because of the melted butter, but do your best to combine them.
- Transfer dough to the prepared baking pan and press/smooth into an even layer. Bake for 26–30 minutes or until lightly browned on the sides and top and a toothpick inserted in the center comes out mostly clean with a few moist (not wet) crumbs. Do not over-bake. If you notice the bars browning too much before 25 minutes, tent the pan with foil. Bars puff up in the oven, but settle as they cool.
- Allow the bars to cool in the pan set on a wire rack for at least an hour. While they’re still warm, I like to press a few more M&Ms and chocolate chips into the tops, just for looks (optional!). Once relatively cool, lift the bars out of the pan using the overhang on the sides and cut into squares.
- Cover leftover bars and store at room temperature for up to 1 week.
Notes
- Make Ahead & Freezing Instructions: You can make the cookie dough and chill it in the refrigerator for up to 3 days or freeze for up to 3 months. Allow to come to room temperature and continue with step 4. Baked and cooled cookie bars freeze well for up to 3 months. Thaw bars overnight in the refrigerator and bring to room temperature before serving.
- Special Tools (affiliate links): 9×13-inch Glass Baking Pan or Metal Baking Pan | Parchment Paper | Glass Mixing Bowls | Whisk | Silicone Spatula | Cooling Rack
- Cornstarch: If you don’t have cornstarch, you can leave it out. The cookie bars will still be soft.
- Butter: Avoid letting the melted butter cool for too long, otherwise your dough will be crumbly instead of soft (and your cookie bars can end up cakey). You want it still warm, but not hot enough to begin cooking the eggs.
- Can I Use Browned Butter? Yes! If you want to amp up the depth of flavor by using browned butter, you absolutely can! My team and I have tested it, and you need to start with an extra 3 Tablespoons of butter to make up for the moisture loss that occurs during browning. Otherwise, the bars will taste dry.
- M&Ms: You can use regular-size, mini, or a mix of both. I like to crush some of them, too, to sprinkle on the top before baking. Totally optional!
- Do I have to add chocolate chips? You can skip the chocolate chips. If you skip them, increase M&Ms to 1 and 1/2 cups (about 300g). You could also replace the chocolate chips with white chocolate chips, butterscotch chips, or peanut butter chips.
- 9-Inch Square Pan: To make a smaller 9-inch pan of cookie bars, use this similar scaled-down recipe for chocolate chip cookie bars. For the add-ins, use 1 cup (200g) of M&Ms and 1/2 cup (90g) chocolate chips.
Reader Comments and Reviews
I’m going to make these for our Christmas lights tour @ our church & was wondering if I could make a couple of batches & bake 2 of them side by side?
Shouldn’t be a problem!
I made these bars with my kids last night. Such a great recipe to do with kids!! They turned out perfectly chew and delicious!! Will definitely make it again. Thanks, Sally!!
My 7year old daughter wanted to make cookies for company. I was short on time and couldnt find the time to roll cookies when I remebered coming across this recipe. She was delighted by the idea and was able to make them all on her own (my double checking she was reading the measurments right. The turned out beautiful and delicious! Just added the recipe to our recipe tin! THanks for sharing!
Sally, Why do you add the salt and baking powder to the sugar/butter mix? In most recipes it is mixed in with the flour.
Thanks,
Katie
Hi Katie! In step two, you whisk the flour, cornstarch, baking soda, and salt together in a large bowl before adding to the wet ingredients later.
Can I use a slightly bigger pan for thinner cookies? e.g. 10×15 inch?
We haven’t tested that size pan – let us know if you give it a try!
I prepared the recipe as directed. Unbelievably, at 25 minutes, they were overdone. The center row was kind of moist but the rest was dry. If I prepare this again I will bake them no longer than 20 minutes.
I had the same problem! Way overdone…ended up with crunchy cookies and I took them out at 24 min.
Hi Sally! Do you think it would be possible to brown the butter for these? Should I increase the amount of butter by a tablespoon or so if I do? Thanks!!! Love all your recipes!
Hi Emma, brown butter would be great in these! You will need to start with some extra butter, yes, so you have 1 full cup for these bars. Let us know if you give it a try!
Any thoughts on cutting the recipe in half and baking in an 8×8″ pan?
Hi Beth! See recipe notes: To make a smaller 9-inch pan of cookie bars, use this similar scaled down recipe. For the add-ins, use 1 cup (200g) of M&Ms and 1/2 cup (90g) chocolate chips.
Delicious! They’re exactly what I wanted them to be 🙂
When I saw this recipe, I had to try it right away. I love M & Ms! The recipe did NOT disappoint! It turned out soft, fluffy, and chocolate-y! Mine didn’t ever get the nice brown color yours have – they stayed pretty blonde, but that didn’t affect the flavor. I also had to bake mine quite a bit longer than the recipe states (almost 20 extra minutes), so maybe it’s time to check my oven temp! Another winning recipe! They will definitely make an appearance at my family’s Christmas Eve festivities! Thank you, Sally & team!
Hi Sally. Just wondering if I could make these ahead of time and freeze them. Thanks
I saw the email with this new recipe and made it immediately! These bars are delicious and are going to be added to my rotation of frequent bakes. Thank you for a great recipe, Sally!
How do you think these would turn out if made in a muffin tin, or whoopie pie pan
Hi Linda, I’m unsure about a whoopie pie pan but I’m sure you can bake this batter in a muffin pan. I’m unsure of the best bake time, because it depends on how much batter/dough you use per cup. A toothpick inserted in the center should come out mostly clean (a few moist crumbs are OK) when done.
Hi, Sally! I have a question. How long does your cookie palooza run for? The cookies all look so good!
Hi Kim! This recipe was the last cookie palooza recipe published this year – we publish 10 brand new cookie recipes over two weeks at the beginning of December. So glad you’re enjoying the recipes!
These look great and easy! I don’t have m&ms at home. Can I use all chocolate chips?
In general, can M&ms and chocolate chips be used interchangeably? Thanks! 🙂
Yes, absolutely!
Hi Sally, I have been using your blog for years, but I think this is my first comment/review. These turned out wonderfully for me. I am baking them for the staff at our small-town hospital (where I work) for Christmas, and so I did a 3x batch baked in a 2/3rds (15″x21″) sheet pan for 30 mins, rotating once, at 375 (my oven runs a little cool, so I often increase the temp from a recipe). I also used my stand mixer to whisk the butter/sugar/eggs, and then transferred everything to a very large mixing/salad bowl to make it easier to combine the dry ingredients. Otherwise I followed the recipe precisely and they came out perfect. I figured I’d share my experience in case anyone else was wondering about making very large batch 🙂 I was worried that the edges would be overdone and the center underdone, but in the end it baked very evenly! I plan to do the same for your salted butterscotch blondies – will see how it goes! Thanks for your amazing and detailed blog. I refer to it all the time. I hope you and yours have a blessed Christmas season!! With gratefulness from Northern Canada, – Meg <3
We’re so thrilled to hear that these cookies were a hit for you, Meg! Thank you so much for making and trusting our recipes.
Can I make this using Gluten Free flour and how much Xantham Gm would I need to add?
Hi Yve, we haven’t tested this recipe with gluten free flours but please let us know how it goes if you do!
This just made my holiday cookie decision easy! Quick question though, is it possible to make these chocolate? I’m assuming more sugar and perhaps a cocoa of stove sort, but if so, how much?
Hi Andy, I’m sure you could play around with the recipe and replace some of the flour with cocoa powder. Or you can use my chocolate cookie dough, use M&Ms instead of chocolate chips, and bake in a 9-inch pan.
Hi Sally could this be made with gf flour instead?
Hi Debbie, I haven’t tested this with gluten free flour but a 1:1 gluten free flour replacement usually works just fine in recipes like this. Let me know if you try it.
Just baked these, following recipe to a tee. Unfortunately, they are a gooey unbaked mess and look nothing like the picture. I think the baking time is off!!
Hi Faye, these usually take between 26-30 minutes, as they aren’t too thick. Are you baking on the center rack and using a 9×13-inch pan? How long did they cool before cutting?
This recipe looks great! Any idea how it would work in a brownie bites pan?
Should work just fine in a square-molded brownie bites pan. Grease the pan and I’m sure it would be the same time a brownie bite takes to bake in there, if you have a particular recipe you use for that.
Hi Sally,
I love your recipes. Always my first stop when looking for something new.
Can smarties be used instead of M & M’s in this bar or cookies in general?
We have a peanut allergy in the family so want to avoid all risk
Thank you
Dee
Yes, the Smarties chocolate candies work here. Not a problem at all.
Do you have to grease the parchment paper
Hi Marie, no need to grease the parchment paper. The bars will lift out of the pan with the parchment to make for easy cutting.
Love all of your recipes, Sally! Do you think I could use peanut M&Ms instead for this recipe?
Hi Renée, you may want to give them a few rough chops since they’re larger than regular sized M&Ms, but that should work just fine!
Hi Sally, my daughter can’t have any dairy. Can I use melted vegan “butter” instead? Thanks!
Hi Alison, we haven’t tested that exact substitution so we’re unsure of how it will work, but let us know if you do give it a try!
Hi, is there a way to adapt the recipe to a 9 inch square pan?
Hi Jack, yes absolutely. See recipe Note.
have made your oatmeal chocolate chip, your lemon ginger (surprise favorite from last year) raspberry almond cream cheese cookies (apricot cream cheese, but subbed in raspberry and sliced almonds. and i will definitely make these too ! Thank you for the ease of this one !! I only trust YOUR recipes for cookies !!! Thank you for all your hard work and happy holidays to you and your family !
Could we store them in the 9×13 pan with a cover? Or do you cut them and put them in a Tupperware container?
I usually cut them outside of the baking dish and then you can put them back in if I’m traveling somewhere with them. Whatever you’d like to do.
Does the baking time change if using a glass baking pan?
Hi Jenny, no it does not. I usually use a glass baking pan for 9×13-inch bar cookies and it’s the same bake time.
I already know that this will be a recipe I like. No chilling, no waiting for the butter to soften. Make the batter , dump in the pan and you’re done!!!
I already made a few cookies from this years’ palooza. These were the ones I baked – Ginger chocolate cookies (which were liked by many), pecan rolled cookies and peppermint cookies rolled in sprinkles. All successes and delicious.
I couldn’t get to the rest because of lack of time but I do want to make them all.
I’m so glad you are finding favorites from this year’s selection! Thank you so much!
Can I use Gluten Free flour?
Hi Sally! Your Holiday cookie posts are one of the highlights for me of the holiday season! A number of your recipes are always on my holiday cookie platters (chocolate kiss cookies, brown butter snickerdoodles, oatmeal raisin cookies, peppermint mocha cookies). And it is tough to just make only that many as all your recipes are so great! I have tried a number of M & M recipes but always find them too sweet for me. This recipe sounds like a winner in terms of toning down the sweetness and being an easy bar form. Can’t wait to try it!
Thank you so much, Julie! I hope you love these. They’re a wonderful treat, and very easy. Much needed after 9 other cookie recipes that require rolling, chilling, slicing, etc. Ha!