Monster cookies are peanut butter cookies packed with chewy oats, chocolate chips, and M&Ms. This recipe for big giant monster cookies yields 2 dozen extra-large cookies that are extra-perfect for cookie monsters who have a hard time choosing between oatmeal cookies, peanut butter cookies, and chocolate chip cookies!
One reader, Rachael, commented: “Amazing cookies! I made these with my son and he is sure that these are your best cookies, Sally! They are chewy in the middle with perfect crispiness on the edges. I will be making these again! ★★★★★”
If you’ve never had monster cookies before, think of a soft peanut butter cookie… now combine that with a chewy oatmeal chocolate chip cookie… now add some mini M&Ms… and add more… and more… don’t be shy! There ya go. 😉
If these look familiar, it may be because these monster cookies are on the cover of my third book, Sally’s Cookie Addiction. As I’m gearing up for the release of my fourth book, Sally’s Baking 101, I decided it was time to revisit a favorite recipe from a previous cookbook era.
This time, I made them even BIGGER.
Tell Me About These Big Giant Monster Cookies
- Texture: Packed with delicious add-ins, these cookies have soft and chewy centers and a delightful mix of textures from wholesome oats and crunchy mini M&Ms. With more oats than flour—more so than my smaller, thick monster cookies—expect a heartier, chewier bite throughout.
- Flavor: Ordinary oatmeal chocolate chip cookies are buttery sweet on their own, but the peanut butter-chocolate pairing brings an irresistible indulgence to every bite. If this flavor duo is a favorite, add these peanut butter chocolate swirl cookies to your list, too.
- Ease: Simple to make, the dough comes together in just minutes using a few staple pantry add-ins like oats and peanut butter. Make them for same-day snacking or prepare them ahead of time for a special occasion.
- Time: This dough can be prepped, chilled, and baked in about an hour! 30 minutes in the refrigerator helps the oats soak up some moisture and prevents the cookies from overspreading.
Best Peanut Butter to Use
Though natural-style peanut butter is my #1 choice for eating and snacking, I recommend using creamy processed peanut butter, like Jif or Skippy, for these cookies.
I recommend the same if you’re making peanut butter chocolate chip cookies or peanut butter snickerdoodles; processed creamy peanut butter means your cookies will hold shape and have the ideal soft-baked texture.
Here is everything you need to make these giant monster cookies:
For today’s monster cookies, the process is similar to many other cookie recipes. Whisk the dry ingredients together (the oats are considered an add-in here!), then use a mixer to cream the butter and sugars together. If you’re interested in learning more, here’s a helpful video and tutorial for how to cream butter and sugar.
- Success Tip: Make sure you start with room-temperature butter. You can’t cream butter and sugar together if the butter is too warm or too cold. (It usually spells disaster for your cookies!) Room-temperature butter is about 65°F (18°C). It’s cool and slightly firm to touch, not overly soft or greasy. I recommend taking the butter out of the refrigerator about 1 hour prior to beginning the recipe to achieve ideal “room-temperature” butter. If you don’t have an hour, here is my trick to soften butter quickly.
Beat in the eggs, peanut butter, and vanilla, then mix in the dry ingredients, followed by the oats. Finally, beat in the chocolate chips and mini M&Ms.
Expect a thick, creamy, sticky dough:
Refrigerate the monster cookie dough for 30 minutes. You can chill it for longer, several days if you need to, but keep in mind that the longer it’s in the refrigerator, the harder the dough will be to scoop.
How to Shape These Big Giant Monster Cookies
After chilling, it’s time to scoop the dough and bake.
I use a food scale to portion out the dough. Each cookie dough ball weighs about 65g (or about 2.3oz), which is a heaping 3 Tablespoons of dough. If you have a large cookie scoop, you can use that, or you could scoop out the dough with a medium cookie scoop (which holds 1.5 Tablespoons) and smush 2 dough balls together.
A cookie scoop is a super handy tool for a sticky dough like this one. If you don’t have one, use a Tablespoon measuring spoon and fill it 3 times per cookie.
As these are XL cookies, you’ll need to bake them in batches. These half-sheet pans are my favorite baking sheets, and I can fit 6 of these monster cookies on each. This gives them enough room to spread out while baking.
While the cookies are still warm, I like to press a few extra M&Ms and chocolate chips into the tops; this is just for a colorful “bakery-style” look.
Yes, you can swap in regular-size plain M&Ms instead of the mini M&Ms. Same amount.
Yes, absolutely! Feel free to use just 1.5 or 2 Tablespoons of dough per cookie. Decrease the bake time by about 2 minutes.
I haven’t tested each and every nut butter in these cookies, but I know almond butter works nicely. The cookies are a bit more crumbly, but it still works.
Yes. Instead, make my oatmeal chocolate chip cookies and sub half of the chocolate chips with M&Ms.
Monster Cookie Variations
- If you love these cookies but don’t have mini M&Ms on hand, try these big fat peanut butter oatmeal chocolate chip cookies instead.
- For smaller cookies with fewer oats, try these soft & thick monster cookies.
- If you love these cookies but need a gluten-free dessert recipe, try these flourless monster cookies instead.
- For peanut butter cup lovers, try these peanut butter cup surprise monster cookies.
- Party of just 1–2 cookie monsters? Try my one giant monster cookie recipe, which makes an XXL monster-sized cookie!
Big Giant Monster Cookies
- Prep Time: 20 minutes
- Cook Time: 15 minutes
- Total Time: 1 hour, 10 minutes
- Yield: 24-25 cookies
- Category: Cookies
- Method: Baking
- Cuisine: American
Description
This recipe for big giant monster cookies yields 2 dozen XL cookies that are extra-perfect for cookie monsters who have a hard time choosing between oatmeal cookies, peanut butter cookies, and chocolate chip cookies!
Ingredients
- 1 and 1/2 cups (188g) all-purpose flour (spooned & leveled)
- 1 teaspoon baking powder
- 1 teaspoon baking soda
- 1 teaspoon salt
- 1 cup (16 Tbsp; 226g) unsalted butter, softened to room temperature
- 1 cup (200g) granulated sugar
- 1/2 cup (100g) packed light or dark brown sugar
- 2 large eggs, at room temperature
- 1 cup (240g) creamy peanut butter*
- 2 teaspoons pure vanilla extract
- 2 cups (170g) old-fashioned whole rolled oats
- 1 and 1/2 cups (345g) mini M&Ms
- 1 and 1/2 cups (270g) semi-sweet chocolate chips, plus more for topping if desired
Instructions
- Whisk the flour, baking powder, baking soda, and salt together in a medium bowl. Set aside.
- In a large bowl using a hand mixer or a stand mixer fitted with a paddle attachment, beat the butter on medium-high speed until smooth, about 1 minute. Add the granulated sugar and brown sugar and beat on medium-high speed until creamed, about 2 minutes. Stop and scrape down the sides of the bowl as needed. (Here’s a helpful tutorial if you need guidance on how to cream butter and sugar.) Add the eggs, peanut butter, and vanilla and beat on high speed until combined, about 1 minute. Scrape down the sides and bottom of the bowl and beat again as needed to combine.
- Add the dry ingredients and oats to the wet ingredients and beat on low speed until combined. Finally, beat in the mini M&Ms and chocolate chips. The dough will be thick, creamy, and sticky.
- Cover and chill the dough for at least 30 minutes in the refrigerator (and up to 4 days). If chilling for longer than 1 hour, allow to sit at room temperature for at least 30 minutes before scooping and baking because the dough will be quite hard.
- Preheat oven to 350°F (177°C). Line baking sheets with parchment paper or silicone baking mats. Set aside.
- Scoop large mounds of dough, 65g each (a heaping 3 Tablespoons of dough per cookie), and arrange 3 inches apart on the baking sheets (about 6 cookies per baking sheet). Bake for 14–16 minutes, or until the edges are set and lightly browned. The centers will look very soft but the cookies will continue to set as they cool.
- Remove from the oven and allow the cookies to cool on the baking sheet for 10 minutes before transferring to a cooling rack to cool completely. While the cookies are still warm, I like to press a few more chocolate chips and M&Ms into the tops—this is only for looks!
- Cookies stay fresh covered 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 4 days. Allow to come to room temperature, then continue with step 5. 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. Read my tips and tricks on how to freeze cookie dough.
- Special Tools (affiliate links): Food Scale | Glass Mixing Bowl | Whisk | Electric Mixer (Handheld or Stand) | Baking Sheets | Silicone Baking Mat or Parchment Paper | Medium Cookie Scoop or Large Cookie Scoop | Cooling Rack
- Peanut Butter: Use a creamy processed peanut butter such as Jif or Skippy. I do not suggest using natural-style peanut butter here, as it yields crumbly, fragile, and sandy-tasting cookies. (Try this recipe for flourless peanut butter oatmeal cookies if you want to use natural!) Crunchy peanut butter is OK, but I find the cookies taste a little dry with it.
- Can I Make These Monster Cookies Nut-Free? Yes. Instead, make my oatmeal chocolate chip cookies and sub half of the chocolate chips with M&Ms.
- Can I Use Another Nut Butter Besides Peanut Butter? I haven’t tested each and every nut butter in these cookies, but I know almond butter works nicely. The cookies are a bit more crumbly, but it still works.
- Be sure to check out my top 5 cookie baking tips AND these are my 10 must-have cookie baking tools.
Reader Comments and Reviews
I made these using natural peanut butter and like you said they crumbled a lot but were still fantastic tasting. Is there any way I can try making these with natural peanut butter? Maybe adding more butter to help hold better?
Hi Alex, we haven’t tried altering the recipe for natural peanut butter, but it would definitely take some tweaking. You might try increasing the butter a bit, but the spread will likely increase that way, too. Let us know if you do any experimenting!
Dear Sally, these Monster Cookies are a Monster hit!
My granddaughter has Celiacs, which as you know is a serious gluten allergy. I noticed your wonderful recipe called for only a small amount of flour,so I substituted gluten free flour,King Arthur brand. I used gluten free oatmeal as well. The cookies were perfect! No one ( except my granddaughter) knew they were gluten free until I told them! They were amazed! These cookies have none of the gritty texture so many gluten free baked goods have. Thank you, thank you, Sally, for a great gift!
Made these and baked just a few as a taste test. Wow, were my taste buds excited by the flavors in these cookies! Yes, a little bit more work but well worth it. Froze the rest in balls ready to bake for future enjoyment! Thanks Sally!
Sally, you mentioned in an old post that Biscoff spread makes a good 1:1 substitute for peanut butter in baking. Like you, I’m addicted to the peanut butter/chocolate/oat combo and regularly bake many of your recipes with these in. When I bake for our community cafe though, I have to keep things nut free and bypass all my favourite bakes 🙁
Have you done much testing using Biscoff as a substitute to make recipes nut free? If not, perhaps you’d like to do this as series of posts for a nut-free audience. I’ve already started with your no-bake chocolate fudge oat bars and blueberry banana breakfast cookies (still 2 pots of Biscoff to go!).
Hi Erica, We haven’t tried Biscoff here, but can’t see why that wouldn’t work! Let us know if you do give it a try.
This was my first time attempting monster cookies and why not start with a trusted source? These were phenomenal and exceeded my expectations. I used peanut butter mini M&Ms and made mine smaller. I froze 2/3 of the dough balls for future cravings.
I made these cookies and they’re absolutely delicious. My question is: Mine don’t come out on the flatter(uniform shape) as yours do. Mine stay kind of like dome shaped. Why is that?
Hi Joanie! Usually when cookies don’t spread, there’s too much flour in the dough. How did you measure the flour? Make sure to spoon and level (instead of scooping) to avoid packing in too much flour into your measuring cups – or use a kitchen scale. You can read more about properly measuring baking ingredients in this post.
Really enjoyed these! And so did my friends!
Looking forward to trying these. Can I use brown butter?
Hi Cheryl, You will need softened butter for these cookies; if you brown the butter, you’ll need to wait for it to solidify before using in this recipe. We also recommend adding a couple Tbsp of milk or cream to the dough to make up for the loss of moisture that occurs when browning the butter, otherwise the cookies might taste dry. Or you could simply start with an extra 2 Tbsp butter before browning to end up with the right amount for the cookies. Hope this helps!
Hi Sally! These cookies look amazing and I am excited to try them. I just want to know one thing: how big are they?
Can I directly triple the recipe or are there modifications?
Hi DeAnna, that should be fine, as long as your mixer and bowl can withstand the added volume. Hope you enjoy the cookies!
Can I make without peanut butter? Would I have to adjust anything?
We’d recommend making these oatmeal chocolate chip cookies instead, and substituting half of the chocolate chips with M&Ms. Let us know if you give it a try!
They’re SO good! Easy to make, easy to eat. I made mine slightly smaller than recommended and even then it seemed like they took forever to bake. Of course, everyone’s oven is slightly different, so… But they were a huge hit and I’ll absolutely make them again.
I made these into bars, as someone suggested. 350 for 26 mins, as per one of your PB bar recipes. I am going to freeze half the recipe because they made so many!! They are delicious!
These cookies are over the top delicious. I used 1/2 cup milk choc chunks and a cup of semi sweet chips. Topped w/ a couple of milk choc chips and mini M & M’s. Soft and chewy. New family favorite.
Amazing cookies! I made these with my son and he is sure that these are your best cookies Sally! They are chewy in the middle with perfect crispness on the edges. I will be making these again!
I needed cookies to take to a BBQ this weekend and found this recipe today. They turned out great! I made them as written…I weighed all ingredients and the cookie balls before baking. The only difference is mine were in the fridge for about an hour before baking. I made two dozen before realizing my cookies were very puffy and tall compared to Sally’s. So I flattened the remaining two dozen dough balls before baking and they looked exactly like hers. Both versions are delicious and my husband says they’re the best cookies ever.
These are 100% as good as they look. I subbed 1/2c chocolate chips & 1/2c mini m&ms for 1 cup shredded coconut, per Sally’s suggestion in the comments & they turned out great. Make sure to read through all the instructions & you will be rewarded with the perfect cookie. Thank you Sally!
Too much going on in this cookie. Won’t make again.
Fantastic recipe! I had an old recipe of monster cookies, and this will be my new go to!
Can these be made smaller?
You bet! See the FAQ section in the post above.
Hi Sally,
Could you make these cookies regular size if you wanted to?
Hi Meg, Yes, absolutely! Feel free to use just 1.5 or 2 Tablespoons of dough per cookie. Decrease the bake time by about 2 minutes.
Another perfect recipe from Sally! As soon as my husband saw the Instagram post of this he asked for them. They turned out perfectly!
Hi Sally,
Can I use regular sized M&M’s? If I can how many cups should I use instead of the minis?
Yes, absolutely! Same amount.
Can I add less sugar or is there any substitute?
Hi Teresa, While you can certainly try reducing the sugar if you wish, keep in mind that it plays an important role in the taste, texture, and overall structure of the cookies. Results will vary with less sugar.
Made the cookies today, they’re delicious!! Is it possible to add some shredded coconut?
Absolutely! You could reduce both the chocolate chips and M&Ms by 1/2 cup each and add 1 cup of shredded coconut.
Going to try that next time I make them, we love coconut!
Hello! Can these cookies be made smaller (perhaps a heaping tablespoonful)?
Hi Karen! See the FAQ section above: Can I make these monster cookies smaller in size? Yes, absolutely! Feel free to use just 1.5 or 2 Tablespoons of dough per cookie. Decrease the bake time by about 2 minutes.
Thank you for this recipe. I’m going to make them as favor’s for a ladies birthday party and wrap them pretty with multi color ribbons and a little note tied to them.
I think they will look very festive!
I love Monster cookies!! They are a perennial favorite.
Sally, I’m wondering if you can speak to the differences in the flourless version and this version with flour.
I’m curious what the textural differences are and why you choose to incorporate flour for your Monster cookies as a regular rule-of-thumb?
Hi Megan! These cookies have a better structure and a fuller, heartier taste. The flourless version is very soft (and very delicious!), but they’re not quite as chewy.
Can this recipe be baked as bars? 9 x 13 pan?
Absolutely! This makes a lot of dough, so I recommend a 9x13inch pan. I’m unsure of the best bake time.
They make mini PB M&Ms now!
Really?? I have not seen them yet! I’ll have to search for them.
Confession: I have always made your monster cookies double the size. They come out with the absolute BEST texture. How they can be dense and light at the same time is a mystery but these get rave reviews from even the biggest peanut butter cookie hater in my family. I like to add peanut butter M&M’s and chopped dark chocolate.
Yes…I add both plain and peanut butter m n m’s…and everything else…and…Also use seasonal m n m’s…
Can I use less peanut butter? I have to eat less sodium. If so, do I need to alter the recipe?
Hi Dot! It would take some testing to reduce the peanut butter in this recipe. You could always try searching for a low sodium peanut butter as well. Let us know what you try!