One Giant Monster M&M Cookie

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Bake my giant oatmeal creme pie next.

One giant peanut butter M&M cookie to cure even the largest peanut butter cookie craving! 

One giant peanut butter M&M cookie to cure even the largest peanut butter cookie craving!

Sometimes you just have a giant peanut butter craving. Mixed with a giant M&M craving, a giant chocolate craving, and a giant cookie craving. So… why fight it?

Before I left for St. Lucia last weekend (what a wonderful trip!!), I surprised Kevin with an extra large cookie when he got home from work.  No reason really – I just personally needed a large cookie and I knew he’d want to share. Although sharing something like this is rather difficult.  Perhaps I should be called fiancé-of-the-year.

One giant peanut butter M&M cookie to cure even the largest peanut butter cookie craving!

The thing is, I love making giant cookies!  And if you have been reading SBA for awhile, you may already know about my affinity for making (and eating) them. The giant cookies are perfect for sharing OR gobbling up all by yourself if you’re extra hungry.

You can make them in less than 25 minutes too! They are each completely oversized and ridiculous in the best way possible:

My giant cookie collection was just begging for a monster cookie. Not sure what a monster cookie is? It’s an oatmeal cookie with peanut butter, M&Ms, and chocolate chips. The monster cookies I prefer, however, are more like peanut butter cookies with oats, not oatmeal cookies with peanut butter.

Still with me?

One giant peanut butter M&M cookie to cure even the largest peanut butter cookie craving!

The cookie isn’t as large as a pizza pie. It’s about 4 regular size cookies combined into one. It’s thick, chewy, and completely irresistible. But that goes without saying, right? Just like my full batch of soft-baked monster cookies, today’s XXL monster cookie will stay soft for days. Well, that’s only if it lasts that long. And trust me, it won’t.

This recipe is like any cookie recipe, just downsized.  A few tablespoons of this, a few tablespoons of that. All of your usual monster cookie suspects: flour, oats, butter, peanut butter, white sugar, brown sugar, baking soda, chocolate chips, and egg. Oh and lots of M&Ms. A note for the egg: all you have to do is crack an egg, beat it, and use 2 Tablespoons of the beaten egg. The ingredients are mixed by hand – no electric mixer needed! That’s my kind of last minute dessert.

One giant peanut butter M&M cookie to cure even the largest peanut butter cookie craving!

If you like cookies, if you like peanut butter, if you like M&Ms, and if you have any sort of sweet tooth – what are you waiting for? 

Follow me on Instagram and tag #sallysbakingaddiction so I can see all the SBA recipes you make. 

More peanut butter/monster cookies to love: peanut butter cup surprise monster cookies, soft-baked monster cookies, big bakery-style peanut butter chunk cookies, chocolate peanut butter macarons, flourless peanut butter brownie cookies, peanut butter cup blossoms, flourless peanut butter oatmeal cookies, and classic peanut butter cookies.

1 Giant Monster M&M Cookie

One giant peanut butter M&M cookie to cure even the largest peanut butter cookie craving!


  • 2 Tablespoons unsalted butter, softened
  • 2 Tablespoons granulated sugar
  • 2 Tablespoons light brown sugar, packed
  • 2 Tablespoons beaten egg (crack an egg, beat it, and use 2 Tbsp)
  • 1/2 teaspoon vanilla extract
  • 2 Tablespoons creamy peanut butter (if using natural peanut butter, use a thick no-stir variety)
  • 6 Tablespoons all-purpose flour (measured correctly)
  • 2 Tablespoons old-fashioned rolled oats (or quick oats)
  • 1/4 teaspoon baking soda
  • 1/8 teaspoon salt
  • 1/3 cup M&Ms
  • 2 Tablespoons milk or semi-sweet chocolate chips


  1. Preheat oven to 325F degrees. Spray baking sheet with nonstick spray or line with a silicone baking mat. Set aside.
  2. In a large mixing bowl, whisk the butter and sugars until creamed. Add egg and vanilla mixing until well combined. Stir in peanut butter then add flour, oats, baking soda and salt. Fold in M&Ms until combined. With a large spoon, scoop into a ball onto prepared baking sheet. The dough will be sticky. Make sure the cookie dough ball is tall and round. Press the chocolate chips into the top of the cookie.
  3. Bake for 20-22 minutes, until edges are lightly browned. The center may appear undone, but it will set as the cookie cools. Let cool ON the baking sheet for 10-20 minutes.

Recipe Notes:

*You may make four smaller cookies using this recipe. Just divide the dough into 4 smaller mounds on the cookie sheet rather than 1 large mound. Bake for 8-10 minutes.

*Want to make a whole batch of monster cookies? Here is my recipe for Soft-Baked Monster Cookies.

Did you make a recipe?

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© Sally’s Baking Addiction. All images & content are copyright protected. Please do not use my images without prior permission. If you want to republish this recipe, please re-write the recipe in your own words, or link back to this post for the recipe. Some of the links above are affiliate links, which pay me a small commission for my referral at no extra cost to you! Thank you for supporting Sally’s Baking Addiction.


So, are you a fan of monster cookies?

My recipe for soft-baked monster cookies is one of the most popular recipes on my website. Countless readers have made them and crown them the best cookies in the world. Trust me, you have to try them!

Monster Peanut Butter Cookies



All Comments

    1. No, it wouldn’t. If you remove the peanut butter, I suggest also removing the oats. The cookie may be too dry with them and without any peanut butter.

      1. I love peanut butter, but I live with someone who is allergic so I just wanted to make a giant oatmeal chocolate chip m&m cookie, but i’m not sure how to do that.

  1. Everything is great! I took the homemade Oreos and cookies to a get together with a friend of mine. By the end of the night everything was gone!! Thank you sooooooooooooooooooooooooooooo much for the GREAT recipes.


    Have you ever tried an XXL normal chocolate chip cookie? I think your the only one on the web with a recipe for XXL cookies, all that comes up are yours 😛 Not that I mind. Your site is the first site that everything I try comes out perfect!

    1. If you remove the peanut butter, I suggest also removing the oats. The cookie may be too dry with them and without any peanut butter.

    1. Hey Stephanie! It would be just fine if you don’t mind some extra nuts in the cookie. I make it with crunchy sometimes, still tastes fabulous.

  3. Truly the BEST giant cookie recipes I have ever tried! Love you and your blog! And thank you sooooo much for the fantastic monster cookie recipe. I had monster cookies at a VBS years ago and never found a recipe that even came close. Happy girl right here!

  4. This is soooo for me: I don’t like sharing my M&Ms or cookies, so making only one M&M cookie will silence the sharing-is-caring people! (hopefully)

  5. Question, Sally,
    I have watched a quite a few food shows, food prep. videos, and prepared many recipes. When following a recipe, is it presumed that you will leave a portion of the ingredients in the bowl or what ever, and that is how portion size is is determined? I may not be making myself clear. For ex. when ever I make corn muffins I follow instructions for how much to fill cups and still have enough for one more. So it is good that I have an individual muffin cup. I scrap my bowls. My kids have always gotten a spoon of cookie dough or cake batter, and I still seem to get 1 more serving than called for. So do professionals not figure on what is left in the bowl? Does it all go down the drain? What a waste. I do the same with toothpaste, shampoo , conditioner and anything in containers. Frugality is the name of the game. Thank you for your time.

  6. Hi Sally! I have absolutely loved all of the recipes of yours that I have tried and so have all of my friends and family. I wanted to know if I could just make an oversized chocolate chip peanut butter cookie, as my pantry is lacking in mini M&Ms and I don’t really like oats. Would I have to adjust anything in the recipe ingredients if I would omit those two? Thanks!

  7. I just made this GIANT cookie- LOVE the recipe! I made a couple changes, and it still turned out great!
    -I didn’t have soft butter, so I microwaved the butter on defrost for 30 sec. Perfect.
    – I didn’t have m&m’s or chocolate, so I used coconut flakes and walnuts.

    I had to cook it for another 6 minutes to get it to cook through, and brown, but now it’s beautiful- golden brown, and perfectly shaped. Thank you!

  8. These cookies are SO good. I make these often for my husband and I! It is a pet peeve of mine when people comment just to say a recipe looks good, but don’t actually make the recipe. So I am here to say that these are the BEST!!! Sally, I would love it if you converted this recipe into a larger batch!

  9. Sally, you mentioned that you use a convection oven for all your baking. For this recipe, do you use 325 degrees even with the convention oven or 300 degrees? Then do you only cook it for 17 or 18 minutes? Thanks. 

    1. Leslie, I use a conventional oven. 325 for conventional for 20-22 minutes. Lower the temp and baking time for convection.

  10. Hello Sally!

    I love your blog! I was looking at all of the delicious recipes and made the Snicker Doodles and Oatmeal M&Ms Cookies. Yum! I kept tooling around for other recipes and found these XXL cookies I would love to make these for the local farmers market — but I would like to make a “batch” of large cookies. Do you have a recipe for them in a larger batch?

    Thank you!


  11. This cookie was OK. It was kind of dry. To be fair, I did not do the instructions that said cool for 10 minutes on the cookie sheet. I may make again and see if I can get it to be less dry and crumbly.

  12. Hi Sally loved this giant cookies and now I am obsessed  tried 3 baths trying to reduce the sugar dough! First did not flatten that much I used salted butter- 2nd double the recipe  made 15 muffin size cookies come out beautiful just forgot to take a picture . I also used one whole small size egg. Wondering why the cookie is not flattening?
    I love all your recipes  

  13. Sally, I made this giant monster cookie and the giant chocolate-chocolate chip cookie this weekend. All I can say is WOW! I think I like this monster cookie even better than your recipe for the full batch. I didn’t have any M&Ms and was too lazy to go to the store, so I used a combo of white/dark/butterscotch chips to sort of make an “everything” cookie. The hubs freakin’ loved it, and he usually doesn’t get too jazzed about anything sweet. The chocolate one was great too, although I forgot to reduce salt since I used salted butter, so it was pretty salty — that was my own fault! It was still delicious, though. These giant cookie recipes are going to be my go-to now. There are only 2 of us, and when I bake an entire batch of cookies, I end up eating most of them myself. Hopefully the giant cookie recipes will help with my inner *need* to bake and not make me need to buy larger pants. Thanks again for all you do! 🙂

  14. Sally, how is it you don’t recommend chilling this cookie dough, whereas for other cookie recipes you always insist on chilling?

  15. 100% making this with cookie butter 😀 I love all of your XXL cookie recipes but cookie butter in place of PB here is definitely a game changer (even though I adore PB) 😉 …my grocery store had a blowout sale on cookie butter for 94 CENTS this weekend. I bought 4 jars. I would have cleaned off the shelf but my teeny kitchen wont allow for that 🙁

      1. Cookie update!! Tried this with cookie butter as promised and the taste and texture was AMAZING!!! My bf said he actually enjoyed this version better than the regular XXL cookie due to the addition of oats. (I saved him half of my cookie, how nice am I, seriously 😉 ) Will definitely make again sometime in the very near future 🙂

  16. Just made these and baked 4 smaller ones instead of one giant one. The recipe says for the smaller cookies, only 8-10 minutes, bit it took me 20 minutes! Next time I would only use half of the sugar the recipe calls for because it was just too overpowering. Other than that, it was delicious! 

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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