These are easily the BEST monster cookies! They’re thick and soft, loaded with oats and peanut butter, and filled with chocolate candies and chocolate chips. This recipe also includes a secret ingredient to help enhance the flavor and texture, making it unlike any other monster cookie.

What makes these the best monster cookies?
With tons of monster cookie recipes out there, why pick this one? For starters:
- The dough does not need to be refrigerated. Just mix and bake!
- It makes thick and huge (monstrous) cookies that live up to the name
- The texture is perfection – a soft and gooey inside with a chewy outside
- It calls for a secret ingredient never used before in a monster cookie that gives these cookies a super rich flavor and texture
I know I’m bias here, but seriously these are SO GOOD! They have the perfect amount of oats and peanut butter to give it that classic monster cookie flavor, but turned up just a bit. After trying these, it’ll be your new go-to recipe.

How to make the cookie dough
This recipe is made just like any other cookie dough, but I’m including a few extra tips to make sure you get it just right!
For starters, combine all of the dry ingredients in a bowl other than the main mixing bowl. This includes quick oats, flour, baking soda, and salt.
In your mixing bowl, whip together the butter, peanut butter, and sugar.
Two things here: make sure to use classic creamy peanut butter like Jif or Skippy…one that you don’t have to mix. If you use a natural peanut butter, the cookies will spread too much and the texture will be completely different.
Second, really whip the three ingredients together for a few minutes until they’re light and fluffy. This helps break down and dissolve the sugar granules so you’re left with a smooth dough. If you don’t mix it enough, the cookies will turn out with a hard crust and cracked surface.
Now comes the fun part…the secret ingredient! Once properly whipped, scrape down the bowl and add vanilla, one egg, and MOLASSES! Give it a good mix until smooth and combined.
Can you taste the molasses?
Yep, this is the secret to getting really rich and chewy monster cookies. The entire recipe only needs 2 teaspoons, so you can’t actually taste it. Don’t worry, they won’t resemble gingerbread cookies one bit. The molasses is only there to help enhance the flavors of this cookie.
It also boost the texture to create extra softness and chewiness. Brown sugar is a combination of regular sugar and molasses, so adding a little extra molasses helps boost the affects of the brown sugar.
I’ve used this exact technique with my halloween candy cookie bars and they turned out so delicious!
Finishing the dough
Once the wet ingredients are well combined, toss in all of the dry ingredients and mix just until they’re absorbed. We don’t want to over mix otherwise you’ll be left with a tough and chewy cookie.

Monster Cookie Mixins
A classic monster cookie includes M&M’s and chocolate chips. For my recipe, I included just these two but you can mix in whatever you want!
Here I used naturally colored candy coated chocolates that you can get at Trader Joe’s or in the bulk food section of your local health food grocer. I love the unique colors it adds to these cookies.
I also used semisweet chocolate chips because they pair really well with the peanut buttery richness of the cookies.
Other mixins include nuts, butterscotch chips, dark chocolate chips or chunks, white chocolate chips, pretzels, toffee, or anything else you have on hand!
Ready to Bake
To bake, scoop the cookie dough using a large 2oz cookie scoop. If you don’t have one, you could also weigh out the dough using a scale. These are monster cookies after all, so they should be a monstrous size!
Bake the cookies at 350F for 15-18 minutes. They’re ready when the centers are puffed and pale and the edges are lightly golden. The cookies will settle and darken as they cool so it’s best to pull them out when they still look a bit underdone.
Let them rest on the cookie sheet for a couple minutes, then transfer to a cooling rack. This makes it easier to move them as they will begin to firm up as they cool.

Can I freeze monster cookie dough?
Yes! To freeze the dough, scoop the dough out onto a small tray or baking sheet. You can line the dough up side-by-side in order to squeeze it all onto the tray.
At this point, you can either pop the dough in the fridge for a couple hours to firm up, then toss the dough balls into a freezer bag. Or you can keep them on the tray and wrap with a couple layers of plastic wrap and then foil.
The dough will keep in the freezer for up to a month. To bake, allow the dough to thaw for about an hour before baking. Then bake as instructed.
Can I use old fashioned oats?
If you only have old fashioned oats on hand, you can use those instead. Just know that the cookies will have a more chewy and bulky texture.
Another option is to take your old fashioned oats and place them in a food processor. Give it a couple pulses to break up into smaller pieces.

For more cookie recipes, check out my:
- Peanut Butter Chocolate Chip Cookies
- Maple Snickerdoodles
- Golden Birthday Cookies
- Salted Caramel Chocolate Chip Cookies
Make sure to tag me @butternutbakery on Instagram and leave a review below if you make these Monster Cookies. To pin this recipe and save it for later, you can use the button on the recipe card, the buttons above or below this post, or on any of the photos above. Happy baking!
Print
Ultimate Monster Cookies
- Prep Time: 20 minutes
- Cook Time: 15 minutes
- Total Time: 35 minutes
- Yield: 12 large cookies 1x
Description
These are the BEST monster cookies. They’re thick, soft, and loaded with m&m’s and chocolate chips. This recipe also includes a secret ingredient to enhance the flavor and texture.
Ingredients
- 1 1/4 cup (125g) quick oats
- 1 cup (125g) all-purpose flour
- 1 tsp baking soda
- 1/2 tsp salt
- 1/2 cup (110g) unsalted butter, room temp
- 1/2 cup (140g) creamy peanut butter, like Jif or Skippy
- 3/4 cup (180g) light brown sugar, packed
- 1/4 cup (55g) granulated sugar
- 1 tsp vanilla extract
- 2 tsp molasses*
- 1 large egg
- 1 cup (185g) M&Ms
- 1 cup (185g) semisweet chocolate chips
Instructions
- Preheat the oven to 350F and line a large baking sheet with parchment paper.
- Combine the oats, flour, baking soda, and salt in a small bowl and set aside.
- In a large mixing bowl with a hand or stand mixer, cream together the butter, peanut butter, and sugar on medium-high speed for a couple minutes until light and fluffy. (see picture in post for reference). Scrape down the bowl.
- Mix in the vanilla, molasses, and egg until fully combined. Scrape down the bowl and give it another mix.
- Toss in the dry ingredients and mix just until the dough comes together. Remove from the mixer and fold in the M&M’s and chocolate chips using a rubber spatula.
- Using a large cookie scoop (2oz) scoop 5-6 cookies onto the baking sheet. Bake for 15-18 minutes or until lightly golden around the edges. If using a regular cookie scoop, bake for 12-15 minutes.
- Let the cookies rest on the baking sheet or a couple minutes, then transfer the cookies to a cooling rack.
- Enjoy!
Notes
*You can’t actually taste the molasses in these cookies. It just helps to enhance the flavors and create a chewy-gooey texture.
- Category: Cookies
- Method: Baked
- Cuisine: American
Keywords: monster cookies, monster cookie recipe, peanut butter cookies
I baked these this afternoon as my reward for cleaning up the basement from a previous day of purging. What a great reward to bake and eat. I could smell the molasses while baking but couldn’t taste it. To be sure, I ate two. I used a smaller scoop to make more cookies so I’m not feeling guilty!. And, I doubled the recipe because if I’m gonna bake, I’m gonna bake. Plus, I have a double wall oven so that makes it easy. Thanks Jenna!!!
Baking these now! Mine are a little smaller and look more puffy, but delicious and super easy to bake!
Thank you!
★★★★★
These were great! Definitely pull them out at the 15/16 minute mark even if you think they aren’t quite done… they shift to overcooked quickly! We just cooked what we could eat as they came out of the oven and froze the rest (and have already defrosted and cooked some of these) — super easy! In these days of quarantine we didn’t have molasses but maple syrup seemed to work perfectly as an on-hand alternative. YUM.
★★★★★
Aw yay! Thanks for sharing Sarah! They’re definitely best a little underdone 🙂
These cookies are perfect. I didnt have peanut butter, and as I wanted to make as soon as I saw the recipe, I replaced with almond butter. I feel like the little bit of molasses took these cookies to another level. Thank you for also including weight measurements for the recipe. Using a scale is so much quicker and precise. Definitely will be making these again.
★★★★★
Yay! Thanks for sharing!
Mine smell good but they fell many fell apart/crumbled in the oven. They didn’t spread like the ones in your photos. I have no idea where I went wrong! 🙁
Sounds like you may have used too much flour! Don’t scoop directly into the bag or flour container, always spoon it into the cup and then level it off.
These were delicious! My husband, who doesn’t like oats in his cookies, LOVED these!! Thanks for the great recipe!
★★★★★
Delicious. I actually made these for my kids intentionally because I’m not a fan of peanut butter… however, these are balanced so well that even I enjoyed them! Subbed out half the butter for yogurt, worked well.
Any goid substitute for the peanut butter?
Sunflower seed butter if you have a nut allergy 🙂
Love the combination of choc chips + peanut butter + oats! Hands down my favorite cookie recipe.
★★★★★
Ah yay! Thank you!
These cookies are so good. I put half peanut butter chips and half chocolate. I also didn’t have molasses so I used corn syrup. My husband who doesn’t like oats loves them!
★★★★★
Sounds delicious!
What a great recipe! I made these last weekend and they turned out beautifully. I appreciate the weight of each cookie ball listed in the instructions. It makes it so much easier to figure out how long they needed to be baked.
★★★★★