Rainbow M&M Cookies

Soft and chewy cookies filled with colorful M&Ms. These are a cookie jar favorite!

Soft and chewy cookies filled with colorful M&Ms. These are absolutely a cookie jar favorite!

These incredibly addicting cookies are super chewy and, by far, the softest cookie I’ve ever baked. They completely disappeared when I brought them into work, with some people even asking me if they were store-bought. Store-bought? The horror!

I adapted the recipe from the famous Cooks Illustrated Chewy Chocolate Chip Cookie.

Rather than melting the butter – as directed in the Cooks Illustrated recipe – I creamed the butter with the sugars and eggs, which produced an exceptionally thick and puffy cookie. Just the way I like them! Another trick to get a thick and puffy cookie is to chill the dough. Like, for hours. Yup… 30 minutes and to up to 5 days of chilling.

Soft and chewy cookies filled with colorful M&Ms. These are a cookie jar favorite!

The unbelievably soft texture and chewiness to this cookie can be attributed to the extra egg yolk. Egg yolks are the source behind a cookies soft texture. This recipe calls for 1 whole egg and 1 egg yolk. Also credited to the chewiness of this cookie is the brown sugar to white sugar ratio. This recipe calls for double the amount of brown sugar to white. So, with double egg yolks and double brown sugar, these babies have double the softness and double the chewy texture!

Make these amazing cookies now and learn why you will use this recipe time and time again!


Rainbow M&M Cookies

  • Author: Sally
  • Prep Time: 40 minutes
  • Cook Time: 8 minutes
  • Total Time: 1 hour
  • Yield: 30 cookies
  • Category: Cookies
  • Method: Baking
  • Cuisine: American


Soft and chewy cookies filled with colorful M&Ms. These are a cookie jar favorite!


  • 2 cups + 2 tablespoons all-purpose flour (spoon & leveled)
  • 1/2 teaspoons baking soda
  • 1/2 teaspoon salt
  • 3/4 cup (1.5 sticks) unsalted butter, softened to room temperature
  • 1 cup packed light brown sugar
  • 1/2 cup granulated sugar
  • 1 large egg, at room temperature
  • 1 large egg yolk, at room temperature
  • 2 teaspoons pure vanilla extract
  • 1 cup mini M&Ms


  1. Whisk the flour, baking soda, and salt together in a large bowl. Set aside.
  2. In large bowl using a hand-held mixer or stand mixer fitted with a paddle attachment, beat softened butter for about 1 minute on medium speed until creamy. Add the brown sugar and granulated sugar, then beat on medium-high speed until creamy and combined. Scrape down the sides and bottom of the bowl as needed. Beat in egg, egg yolk, and vanilla extract. Scrape down the sides and bottom of the bowl as needed. With the mixer running on low speed, slowly add dry ingredients to wet ingredients. Pour in the M&Ms and beat on low speed for 20 seconds or until combined. Once completely combined, cover cookie dough tightly and chill in the refrigerator for 30 minutes and up to 5 days.
  3. Preheat the oven to 325°F (163°C). Line a large baking sheet with parchment paper or a silicone baking mat. Set aside.
  4. Remove cookie dough from the refrigerator. Drop by Tablespoonfuls onto prepared baking sheet. Bake for 8-10 minutes or until edges are slightly browned. The centers should appear very soft and puffy. If desired, press a few mini M&Ms into the tops of the warm cookies for looks. Repeat with remaining cookie dough.


  1. Make Ahead & Freezing Instructions: Cookies stay fresh covered at room temperature for up to 1 week. You can make the cookie dough and chill it in the refrigerator for up to 5 days. Allow to come to room temperature and continue with step 4. Baked cookies freeze well for up to 3 months. Unbaked cookie dough balls freeze well for up to 3 months. Bake frozen cookie dough balls for an extra minute, no need to thaw. Click here for my tips and tricks on freezing cookie dough.
  2. Keep Dough Cold: Make sure to keep dough cold at all times while the batches are baking. I keep my dough in the refrigerator in between batches.
  3. Add-Ins: You can easily swap add more add-ins to these cookies (chopped candy bars, nuts, chocolate chips, etc) as long as the total does not go over 1 cup. Get creative!
  4. Be sure to check out my top 5 cookie baking tips AND these are my 10 must-have cookie baking tools.

Keywords: m&m cookies


  1. Hi Sally! I LOVE your blog and have had great luck with everything. Just wondering–is there a reason why you use salted butter in this recipe?

    Thanks so much,

    1. Hi Betsy! I actually prefer salted butter in most of my cookie recipes, but write them with unsalted butter since that is what most people use anyway. I like the slight increase in saltiness. You may use unsalted here, without changing anything else about the recipe.

  2. I just made these with my daughter-her request…m&m cookies, but NOT monster cookies. We were just tasting the dough, when it dawned on me…there is no salt in the recipe! Yikes…I like salty with my sweet. BUUUUUT, I will try them as is for the first batch, then sprinkle salt on top if I need to. Chilling as we speak, I’ll let ya know!

    1. Oh.my.gosh! I JUST noticed the comment above mine, and did not realize the recipe called for salted butter. Great. This is why I can’t bake. I’ll cook any day and all day, but baking—just not enough wiggle room for me!

  3. I made these for my son’s preschool class…so yummy! Incredibly sweet, and moist. Love your blog..you are incredibly talented! Thank you for sharing :)!

  4. This recipe sounds sooo good, but is it possible to cut the recipe in half. I would like to put them in mason jars that I have for a shower favor (quart size) but it’s just difficult to fit it all in the jar. All the ingredients seem simple enough to cut in half…but the egg is the problem. Any suggestions. Thank you

  5. i LOVED the dough, but had to increase baking time by 7 minutes at 325, and they were still a bit undercooked for my taste. I increased the temp to 350 (using convection setting this time), but still required baking for 12 minutes. The final product was wonderful, though! The recipe is a keeper with the changes I mentioned, thanks!

  6. Hi, Sally!

    I have a question about these delicious cookies.
    I’m making a “cookie cake” for my son’s birthday, and was wondering if the large cookie would turn out as well as the individual small ones. We’ve made these before, and LOVED them, but I was just wondering if it’d work on a larger scale.

    1. A cookie cake would be delicious Victoria! I am unsure of the bake time though. Probably similar to this: https://sallysbakingaddiction.com/2014/03/18/chocolate-chip-cookie-cake/

  7. Hi Sally! Anytime I try this recipe, something goes wrong. Either my dough does not form and becomes crumbly, or my cookies are as flat as pancakes. Any idea on what I could be doing wrong? Thanks in advance!

    1. Karina, are you changing anything about the recipe at all? Make sure you are measuring your flour correctly (spoon and level) and chilling the dough. Do you bake cookies on a silicone baking mat? (Such as Silpat)– I find my batches of cookies bake wonderfully each time using one.

  8. Mine are taking forever to cook! About 12-13 minutes and the centers are still ‘gooey’. Should I turn it to 350 next time?

  9. Please could you provide the numger of grams of m&ms needed? I also can only find the normal sized m&ms in the UK – will that suffice?


    1. Until room temperature – I’d say at least an hour. For the egg, set it in a glass of warm water for 10 minutes.

  10. Hello,
    Could I make this recipe with peanut m&ms?
    I have been having difficulty finding a peanut m&m cookie that doesn’t involve a peanut butter cookie base. 

  11. So I literally just combined the ingredients to these Rainbow M&M Cookies and put them in the fridge to chill. It wasn’t until after I combined everything that I read that the add-ins should not exceed one cup. I’m making blue and yellow m&m cookies for a baby shower and it didn’t look colorful enough so I added extra m&m’s, about an additional half cup extra. Is that going to hurt the look/taste of the cookie? I’m baking them tomorrow evening. Baby shower is Saturday the 23rd. 

  12. Baking these on a humid day, so having some spreading issues. Sally, how do you combat humidity? Also, I’m seeing some people referencing cornstarch, but I don’t see this in the recipe…

    1. Hi Jenn! I use cornstarch in a lot of my cookie recipes (after posting this one back in 2012), so you can add a teaspoon to this cookie dough if you’d like. Just makes the cookies a little softer. On super humid days, sometimes I add 1-2 more Tablespoons of flour and chill the cookie dough for at least 1 full day in the refrigerator.

      1. Thanks, Sally! I receive so many compliments when I bake from your recipes. I love that I’ve learned so many techniques from you (dough chilling and cookie towers for baking have been a game changer!).

  13. Hi Sally!
    I was wondering if you could share the recipes in grams? 🙂 
    I’d be highly grateful!

    Thank you!

    P.S. Your recipes are amazing! 😀

  14. Hi Sally, I made these and they’re as flat as pancakes 🙁 was going through the other comments when I noticed someone asked if its ok to omit cornstarch, but I can’t find a mention of cornstarch in your recipe. 

  15. Hi Sally,
    congratulations for the blog!
    I’m Italian but I love American recipes
    Can i ask you the conversion of the ingredients in gram ?
    Thank you


  16. Hey Sally,
    I made your rainbow m&m cookies, but i realized that the dough was way to thin. Do you know what the problem is? I added the right proportion everything.

  17. Just made a batch of these, they are amazing! I had to taste one when they were still warm and I thought, OK, not bad. But when they cooled down, I tried another and OMG, I was blown away! Yummy and very easy to make, I followed your recipe to a T, and they came out perfect!

  18. Dear Sally,
    I’m going to make these batch of M&M later but I want to ask you if I could make double batch to make it extras? How can I make double plz add one more flour or butter or what?! I appreciate if you could reply me sooner plz cuz I’ll makenit today for birthday party on Friday! By the way I made crinkle n I was amazed n blown away with these crinkle!!!! All my family have eaten all so fast!!!! I love your blog n ever since I use your recipe I keep following you everyday!!!! Keep it up!

      1. Thank u so much for replying fast!!! How can I double recipe ? Shall I repeat again the sama entire recipe? Here said for example 2 cups flours which make 4 cups of flours or shall I repeat the entire same recipe? Sorry for asking much!!!

  19. Hi Sally,

    These look great and I plan on making them for the holidays with red and green colored m&ms. I read some of the comments about cornstarch but can’t seem to find it in the recipe list. How much would you recommend adding to the above recipe?

  20. Hi Sally,

    I have tried many of your recipes, and they were all amazing! I only use your recipes as I know that they will turn out well. These cookies were easy to make and were so yummy. Thanks for all of the incredible recipes!


  21. Hi, first of all, i have loved all of your recipes!
    If I make these ahead of time and refrigerate for a few days. Do I let the dough come to room temp before baking? It does say that in the recipe, but farther up in the recipe it says to remove from the fridge and bake. I’m sure it doesn’t matter that much but if it does, please let me know!

    1. Hi Susan! I recommend waiting for at least 30 minutes if the cookie dough has chilled for a few days. It will be pretty hard, so letting it slightly soften will help with rolling.

  22. I have made these twice now. They are an easy crowd pleaser! However I have found that I need to basically double the bake time to avoid just having raw dough (they are still soft). My oven is new and true to temp, so folks might just want to add some more time if they seem wayyy too soft.

  23. Hi Sally, how can we substitute almond flour for regular flour? Is it the same ratio? Trying to make these cookies for a gluten free friend!

  24. Sally, I am at a total loss. I cannot seem to bake cookies that remain thick and fluffy. I just made these for Valentines and they are flat. I followed the recipe exactly. I put them in the fridge overnight and baked the next day. I tested my baking sofa and it is still good. This happens to me every time I bake which is a lot! Please help!

    1. Hi Carrie, have you taken a look at this post to help troubleshoot? https://sallysbakingaddiction.com/tips-for-cookie-spreading/
      When in doubt use the spoon trick at the end to save them!

      1. Thanks for answering! Yes, I have read all your tips! This seems to happen with so many of my cookie recipes(from your site and others). I didn’t but cornstarch in these bc it wasn’t in the recipe but then I was reading comments about adding it….
        I am just wondering what I am doing wrong. I literally have read a million articles on it haha!

  25. It’s tough to find brown sugar (soft, like wet sand, American style) in Spain. I found something called “Panela” that seemed sort of similar in texture… it said it was from Colombia on the bag. Have you ever cooked with this? It smelled and taste a bit different and still wasn’t quite as soft, but closest thing I could find.

    I made the dough with it, still chilling in the fridge. I wanted to make these for my birthday, I’m worried I may have flubbed this.

    We’ll see…..

      1. Thank you, Sally! It actually worked out as a substitution! The taste is very slightly different than with our American-style brown sugar, but the cookies are still very good. Apparently, panela (also known as rapadura) is unrefined whole cane sugar, typical of Colombia, Central, and of Latin America in general. So hopefully this helps any of your readers located in those regions.

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I’m Sally, a cookbook author, photographer, and blogger. My goal is to give you the confidence and knowledge to cook and bake from scratch while providing quality recipes and plenty of pictures. Grab a cookie, take a seat, and have fun exploring! more about Sally