Today, I’ve got the most amazing soft and chewy monster cookies that are loaded with oats, peanut butter and m&m’s. These no chill cookies are uber simple to make, easily feed a crowd and are perfect to bring to your next potluck or BBQ. They can also be made in one bowl and are a great, simple cookie for the kids to help make.
I first discovered monster cookies while living in the United States, where I attended the University of North Dakota. I saw these ginormous, delicious looking cookies at all the local coffee shops but had no idea what they were. A friend bought one, one day and shared with me, wow was I hooked. The coffee shop near the rink where I worked sold them and I use to study there in between jobs and class. Some days I had to talk myself out of buying a second one.
These cookies are now one of my family’s favourites’ and literally eaten by the stack. They’re such a simple recipe and I’ve purposely created the recipe so it’s almost impossible to not end up with a beautifully soft cookie with perfectly crisp edges.

If you’d like something a little different, try my monster cookie icebox cake. It’s basically a deconstructed monster cookie that if frozen tastes like an ice cream cake! Otherwise, try my pumpkin monster cookies for a beautiful twist with some additional spices.
FAQ: Soft & Chewy Monster Cookies
Why Are My Monster Cookies Dry?
Most likely due to overbaking or adding too many oats. Only bake the cookies until the edges just start to feel firm. When measuring your ingredients, measure by weight if possible.
Why Did My Cookies Spread So Much?
This could be due to your butter being too warm. You want it at room temperature, so you should be able to push an indent into the butter. If it’s really easy and your finger just goes right in, then it’s too warm.
How Do I Make My Cookies Look Like Bakery Cookies?
Add additional m&m’s and chocolate chips on top of the scooped cookies prior to baking. Immediately after removing the cookies from the oven, swirl a glass or bowl around the edges of the cookies in a circular motion to bring them into a perfect circle.
Can I Make These Without Peanut Butter?
I have not tested this recipe with other nut butters but I wouldn’t use a runny nut butter.

Making Gluten Free Monster Cookies
Just ensure your oats and m&m’s are gluten free. These cookies are flourless so they are very easy to make gluten free.
As a side note, if baking anything gluten free for someone with an allergy, ensure you thoroughly wash any equipment, baking mats and trays. Any contact with flour may trigger an allergy. I like to say any baking I do in my own home is gluten friendly as I am using flour often and cannot guarantee there’s been no cross contamination.
If you’re interested in other gluten free recipes, try my almond flour chocolate chip cookies or my fudgy coconut flour brownies. Or for a healthier option, try my chocolate almond banana muffins.
How to Freeze and Bake No Chill Cookie Dough
If you’d like to freeze the dough to save time in the future, follow these simple steps.
- Prep the dough as instructed.
- Roll the dough into balls.
- Place in an airtight container or bag.
- Label with type or flavour of dough, date, bake time and baking temperature. This makes life much easier when you pull the bag out of the freezer in a couple months and have forgotten what it is. (If you’re using a reusable bag, you can just write this information on a piece of masking tape or something similar.)
- Store in freezer for up to 3 months.
- When ready to bake, preheat your oven and place balls on baking sheet.
- Add 1-2 minutes to bake time as baking from frozen and enjoy!
Best Way To Store Cookies
The best way I’ve discovered, half through accident and half through social media is in an airtight container with 1-2 marshmallows. I first noticed how fresh my cookies were staying when I had them in the same container as my rocky road squares but didn’t think much of it. Then I saw someone recommend adding marshmallows to your cookie container somewhere on the internet and it clicked in my brain why the rocky road squares were making a difference. It’s amazing how much the marshmallows help keep the cookies from drying out!
If you don’t have marshmallows, a slice of bread also works but try not to let it touch the cookies.

Baking Tips
- Ensure the peanut butter you use is creamy and smooth. I made these once with a no name peanut butter and I’m assuming due to a lower fat content, they turned out terribly. They weren’t nearly as moist and didn’t bake properly.
- I typically make these as heaping tbsp size cookies but you can absolutely make them bigger. I’ve done 1.5 tbsp size and 2 tbsp size. Both were delicious, but keep in mind, the bigger they are, the more gooey they’ll be in the centre and you may have to alter the bake time a little.
- For best results, ensure all your ingredients are room temperature. This allows your ingredients to incorporate into each other leading to a much better bake and texture.
- I create my recipes based off weights so I recommend measuring by weights if you own a scale. It’s actually so much easier and makes for much less cleanup. I wish I had baked by weight from the beginning, I could never go back now.

More Cookie Recipes
My song today is such a feel good song that always puts a smile on my face. It’s one of my favourties to dance around my kitchen too. Here’s Good Day by Nappy Roots. Happy Baking! **Disclaimer: Liv’s Little Muffins owns no rights to this song.
Don’t forget to leave a STAR REVIEW if you try my recipe! Follow me on Facebook or tag me on instagram @livslittlemuffins. Find more ideas on my Pinterest or Whisk.

Soft & Chewy Monster Cookies
Ingredients
- 1/2 cup (113g) unsalted butter , room temperature
- 1 cup (200g) granulated sugar
- 1 cup (180g) brown sugar (packed)
- 1 1/2 cups (330g) smooth peanut butter
- 3 large eggs
- 1 tsp vanilla extract
- 4 cups (480g) quick oats (gluten free if needed)
- 2 tsp baking soda
- 1/2 tsp salt
- 3/4 cup (160g) m&ms
- 3/4 cup (120g) semi sweet chocolate chips
Instructions
- Preheat oven to 350℉ and line a baking sheet with silicone mat or parchment paper.
- In the bowl of a stand mixer or large mixing bowl, add your butter and sugars. Beat for 1 minute on medium-high speed.
- Add your peanut butter and beat for additional minute.
- Mix in eggs, one at a time until fully incorporated.
- Stir in vanilla. Then add your oats, baking soda, and salt. Mix at low speed until combined.
- Add in the m&ms and chocolate chips. Mix until combined.
- Scoop by heaping tbsp onto your cookie sheet. Bake for 11-13 minutes or until the edges start to slightly brown.
- Let fully cool before storing in an airtight container for up to 5 days and enjoy!








