Tessa's Recipe Rundown
TASTE: Loads of peanut butter, oats, chocolate chips, and M&Ms make these cookies so much FUN!
TEXTURE: Delightfully chewy thanks to the oats and peanut butter, with a subtle crunch from the chocolate chips and M&Ms throughout.
EASE: So easy! These cookies are ready to enjoy in just 33 minutes.
WHY YOU’LL LOVE THIS RECIPE: A family staple with no chilling required, but also freezer-friendly.
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I’ve written an entire cookbook about cookie baking, and my cookie science experiments have been featured on NPR and People magazine and have even been used in university curriculums!
Needless to say, I love cookies. And my Monster Cookie recipe is something special. Thick, chewy, and loaded with my favorite ingredient… nostalgia 😉
It’s the perfect recipe for back-to-school season, Halloween, Christmas, or just any time I’m craving peanut butter and chocolate…which is basically every day, ha!
Because it’s such an easy recipe, it’s a great one to make with kids. Oh, and it’s naturally gluten-free (if using certified GF ingredients)!
Sprinkle of Science
How to Make Amazing Monster Cookies
No Flour in This Monster Cookies Recipe?
Yes, these Monster Cookies are flourless cookies. The peanut butter, oats, and egg + egg yolk provide enough structure to hold everything together and bake into a chewy delight.
The lack of flour does change the texture of the dough. It will feel a bit loose and won’t hold together like a traditional cookie dough. This means that a few of the M&Ms and chocolate chips may fall out as you portion out the dough. That’s okay – simply add them back on top of each cookie dough ball! No biggie.
What Type of Peanut Butter is Best for Monster Cookies?
I recommend using natural peanut butter that’s been very well stirred (no oily pockets or dry bits).
My favorite is Kirkland Organic (high quality and a great price at Costco!). Natural peanut butter will yield a much bolder peanut butter flavor in these Monster Cookies. If you don’t have any, conventional peanut butter (Skippy / Jif) works well too.
What Type of Oats for Monster Cookies?
Use old-fashioned rolled oats for Monster Cookies. Don’t use quick oats, which can make the cookies mushier and less chewy. Be sure to measure correctly, as accidental over-measuring can cause dry, hard, crumbly cookies. Learn more about how to measure ingredients correctly here.
Do I Have to Use Dark Brown Sugar?
I recommend using dark brown sugar for its added flavor and moisture to achieve a rich and chewy cookie. You can use the same amount of light brown sugar instead, but note that your cookies may turn out lighter in color and slightly less moist.
Can I Use Almond Butter Instead?
We haven’t tested that in this Monster Cookie recipe, but a straight 1:1 swap of almond butter instead of peanut butter works perfectly in my Classic Peanut Butter Cookie recipe. Let me know if you give that a try here!
What Size Are These Monster Cookies?
I use a large 3-tablespoon cookie scoop to create perfectly chewy cookies. You can use a medium 1.5-tablespoon scoop instead and reduce the bake time by 1-2 minutes, but keep in mind that the smaller cookies won’t be as chewy.
Can I Mix up the Mix-Ins?
Yes! Feel free to use peanut butter chips, chopped Reese’s Pieces, or any other variety of mix-ins you like in these Monster Cookies – just keep them small in size and the total weight/volume the same amount for best results.
How to Prevent M&Ms From Cracking as They Bake
- Some bakers say that mini M&Ms are less likely to crack, and others claim that freezing your M&Ms prior to baking prevents cracking. I haven’t tested either theory, so I can’t say for sure how well they work.
- If the cracking bothers you, I recommend adding the additional M&Ms to the tops of each baked cookie as soon as they come out of the oven, before they have fully set.
- Be sure to press the M&Ms into each cookie thoroughly to ensure they adhere properly.
Can I Double This Recipe? Can I Halve This Recipe?
Yes! Double all ingredients to yield approximately 34 large cookies, or halve all ingredients to yield 8-9 large cookies. No other modifications needed.
Do I Have to Chill Monster Cookie Dough?
No, you can bake these Monster Cookies right after preparing the dough.
For extra chewy, ultra-flavorful cookies with a ton of PB flavor, I recommend chilling the cookie dough for 24 to 48 hours.
Avoid chilling any longer, as oats tend to zap moisture and these cookies will dry out. Learn more about how to chill cookie dough here.
How to Store Monster Cookies?
Monster Cookies can be stored in an airtight container at room temperature for up to 3 days. Store with a tortilla to keep the cookies softer for longer.
Can You Freeze Monster Cookies?
- Yes, Monster Cookies freeze well!
- If chilling the dough, do so before freezing.
- Place scoops of dough in a single layer on a parchment-lined rimmed baking sheet and place in the freezer until solid. Remove scoops to a labeled and dated airtight container.
- Bake directly from the freezer by reducing the oven temperature to 325°F and adding a minute or two to the bake time.
- Learn more about How to Freeze Cookie Dough (& Bake From Frozen) here.
More Cookie Recipes You’ll Love:
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Ingredients
- 4 tablespoons (57 grams) unsalted butter, at cool room temperature
- 3/4 cup (203 grams) natural peanut butter, very well stirred*
- 1/2 cup (100 grams) granulated sugar
- 1/2 cup (100 grams) lightly packed dark brown sugar**
- 1 large egg plus 1 egg yolk, at cool room temperature
- 1½ teaspoons vanilla extract
- 2 cups (198 grams) old-fashioned rolled oats
- 1 teaspoon baking soda
- 1/4 teaspoon fine sea salt
- 1/2 cup (85 grams) semisweet chocolate chips, plus extra for garnish
- 1 cup (200 grams) M&M candies, plus extra for garnish
- Flaky sea salt, for topping, optional
Instructions
- Preheat the oven to 350°F. Line baking sheets with parchment paper.
- In the bowl of an electric mixer, beat the butter, peanut butter, granulated sugar, and brown sugar on medium-high speed until smooth and creamy, 2 to 3 minutes. Scrape down the bottom and sides of the bowl. Beat in the egg, egg yolk, and vanilla. Add the oats, baking soda, and salt, mixing on low speed until combined. Fold in the chocolate chips and M&Ms with a rubber spatula.
- Using a large spring-loaded scoop, measure out 3 tablespoon-sized balls of dough. Press the dough firmly into the scoop before placing it onto prepared baking sheets, spacing at least 2 inches apart. Dough will be loose. Dot the tops of cookies with a few M&Ms and/or chocolate chips before baking for picture-perfect cookies.
- If time permits: wrap the cookie dough balls very well in plastic wrap and allow to “marinate” in the fridge for 24-48 hours to enhance flavor and texture.
- Bake for about 13 minutes, or until the edges are slightly browned. Remove from oven and sprinkle flaky sea salt on top of the cookies, if desired. Cool for 5 minutes before removing to wire racks. For best texture and to allow the peanut butter flavor to fully develop, let cookies cool completely before serving.
- Cookies can be stored in an airtight container at room temperature for up to 3 days.
Notes
Photos by Joanie Simon.
These were so easy and so good! I will definitely be making them again. 🍪
These cookies came together so quickly. The recipe was super easy to follow and the cookies came out great.
I got 16 cookies out of this recipe. I initially didn’t refrigerate them, I missed that step when I first read the recipe and didn’t want to wait until tomorrow. So the first tray I made got way too spread out. They still tasted good! Just got a lot bigger than I would have liked. So for the second tray, I stuck them in the freezer for 30 minutes before putting them in the oven. This worked great and they stayed to a more medium size. I would leave them in the oven for an extra minute or two next time, as the frozen batch didn’t look quite as done on top. 13 minutes was perfect for the non-refrigerated ones however. Also, I used Reese’s Pieces instead of M&Ms, as that’s what I had on hand, and also I thought the colors were more festive for Halloween. I did find that the batter was too dry for all the mix ins to thoroughly incorporate, so I ended up adding in the extra egg white I had left over, and that worked well to bring it all together. More than any cookie I have ever had, the flavor of these cookies in enhanced enormously when dipped in milk!
These are so delicious and easy to make! I love that they don’t have flour in them!
These cookies are AMAZING!! I’m not usually into oatmeal cookies, but these are exceptional and I will definitely be making them again. Perfect texture, perfect flavor, zero downside! I also froze some extra cookie dough balls and have baked them from frozen with the same results. Thank you!!
Woohoo! So happy you loved them, Gabs!
These were my favorite monster cookies I have made so far! The texture stayed great for days.
I always forget the stars until after I submit the review 🙁
Very easy and a crowd pleaser! They definitely took longer than 13 minutes in my oven. Also, chilling them in the fridge for a day made the flavor much richer, so I recommend that.
Oh I’ve waited a long time for this recipe; I don’t trust anyone’s cookie recipes except for yours! Currently “marinating” but the dough itself is already five stars! 🤩
Ah, thanks, Angela! You’re too kind 🙂 Excited to hear what you think after you take your first bite!
My family enjoyed these cookies. We even took them with us on a train trip. They held up well and were a nice treat when we got back to the hotel after a long day of sightseeing. I think if I made them again, I would use mini versions of the M&Ms and chocolate chips.
Made them fresh right before going off to college, very nicee
Forgot the star, but 5 stars all the way! Gluten-free too.
So much goodness in these that we were able to convince ourselves they were ‘trail mix cookies’ — a healthy choice!