Monster Cookies

These gluten-free Monster Cookies will make everyone smile! What's not to love about a peanut butter* oatmeal cookie with lots M&Ms and chocolate chips? *Substitute your favorite nut or seed butter.

gluten free monster cookies #glutenfreerecipes
Monster Cookies

Easy, Soft & Chewy and Yummy!

For Monster Cookie BARS, click here.

New! I’ve added a cooking video to this page so you can see how quick and easy it is to make these gluten-free Monster Cookies!

If you’re new to the website, I have a printable recipe on the bottom of every recipe page with exact measurements and directions.


Update Fall 2020: It’s Halloween Week!

If you’re looking for Mini Twix Bars, click here.

If you’re looking for Mini Peanut Butter Cups, click here.

If you’re looking for Gluten-Free Monster Cookies, a super easy, fun and yummy Halloween Treat, read on!

gluten free monster cookies #glutenfreerecipes

Original post…

Who else loves a Monster Cookie?

What’s not to love about a peanut butter oatmeal cookie with lots of chocolate chips and M&Ms?  (Feel free to substitute your favorite nut or seed butter by the way!)

We started with our favorite Peanut Butter Cookies, which are a long time family recipe… made some tweaks and added some gluten-free oats, chocolate chips & M&Ms.

And they are a total hit!

gluten free monster cookies #glutenfreerecipes

Best part? The are super easy to make and are made with pantry staples, except for the M&Ms which I happened to have picked up while stocking up on essentials at the store the other week.

All you need is ….

butter or dairy free butter

brown sugar

cane sugar

vanilla extract

eggs (I haven’t made them with flax eggs but provide my recommendation)

peanut butter

gluten-free flour (we used GF Jules, affiliate link)

baking soda

gluten-free baking powder

a pinch of salt

gluten-free oats (we used GF Harvest, amazon affiliate link)

chocolate chips

M&Ms (or a similar brand chocolate candies)

gluten free monster cookies #glutenfreerecipes

As an aside, you may have noticed that we are affiliate for GFJules.  To learn more about why we love GFJules flour and why we have used it for 10 years, click here.

Bonus: at the bottom of that post is a one-time use affiliate Discount Code.

And importantly, purchasing through an affiliate link does not change your cost at all. It generates a small percentage of the sale for me, and purchasing through an affiliate link helps me fund this website and all the recipes I share, so thank you!

Easy gluten-free monster cookies

A note about Oats: Oats are naturally gluten-free BUT they are prone to cross contamination in the growing process which is of concern for people who are gluten-free for medical reasons such as celiac disease.

The safest gluten-free oats are grown via a process known as purity protocol to eliminate cross contamination.

As the demand for gluten-free products has grown, many manufacturers use gluten-free oats that are sorted and there are questions surrounding this practice.

Gluten-Free Watchdog has done lots of research and writing about this topic to which I’ve linked to if you want to read more.

I’m also linking to a post by GF Jules about this topic and to the Gluten-Free Watchdog list of Oats grown under Purity Protocol.

Back to the Gluten-Free Monster Cookies…

They are super easy to whip up!

Using a hand mixer or stand mixer (we love our Kitchen Aid-amazon affiliate link, as you know!) or even mixing by hand, beat the butter, sugar and vanilla.

Then beat in the eggs and peanut butter.

Add in the flour.

Then the oats. Then stir in the chips and M&Ms leaving some aside for topping if desired.

Roll into balls, press down gently and top with the extra m&ms and extra chips if you like.

The entire process takes 15 minutes or less!

Bake for just 10 minutes and enjoy!

gluten free monster cookies #glutenfreerecipes

Hope you love them as much as we do!

Scroll down for recipe and leave a comment if you try.



Gluten-free Monster Cookie Bars easy baking gluten-free dessert recipe
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4.72 from 7 votes

Monster Cookie Bars

An easy, recipe for a fun, yummy and crowd-pleasing dessert! These bar cookies are soft and chewy, just the right amount of peanut butter (substitute your favorite nut or seed butter) and gluten-free oats, and lots of chocolate chips and M&Ms!
Prep Time15 minutes
Cook Time25 minutes
Total Time40 minutes
Course: Dessert, Cookies, Bar Cookies
Cuisine: Gluten-Free, Dairy-Free Optional, Nut-Free optional
Keyword: easy gluten free dessert recipe, easy gluten-free cookie recipe, easy gluten-free baking, gluten free bar cookies, gluten-free monster cookie bars, gluten-free halloween treats, gluten-free holiday dessert
Servings: 24 bars
Author: Healthy Gluten-free Family


  • 1 9x13 inch pan


  • ¾ cup butter or dairy-free butter, softened (1 ½ sticks )
  • 1 cup brown sugar packed
  • cup cane sugar
  • 2 teaspoons vanilla extract
  • 2 large eggs
  • ¾ cup peanut butter or nut/ seed butter of choice I used Natural Creamy Peanut Butter (not the bottom of the jar if possible)
  • 1 ½ cup gluten-free all purpose flour with xanthum gum* (We used GF Jules flour, Affiliate Link)
  • 1 ½ teaspoon baking soda
  • 1 teaspoon baking powder
  • ½ teaspoon salt
  • 1 ½ cups gluten-free oats
  • ¾ cup semi-sweet chocolate chips or chips of choice
  • ¾ cup M&Ms or chocolate candy of choice plus 1/2 cup more for topping


  • Preheat oven to 350 degrees F and line a 9x13 inch pan with parchment paper, or grease pan very well. Set aside.
  • Using a stand up mixer or hand mixer, mix butter, sugars and vanilla until well combined and creamy.
  • Add eggs and beat thoroughly.
  • Beat in peanut butter.
  • In a separate small bowl, add flour, baking soda, baking powder and salt. Mix with a fork or pastry cutter. Then add the flour mixture to the creamed mixture and mix until combined.
  • Add in oats and mix till combined.
  • Add in chocolate chips and m&ms and gently mix till combined.
  • Spoon batter into the prepared baking pan and spread evenly. Top with additional m&ms, pressing gently into the batter.
  • Bake for 25 minutes, or until golden and a tooth pick comes out clean. You do not want to over-bake.
  • Let cool in the pan for 45 minutes or longer. Lift the entire parchment paper out and transfer to a cutting board. Cut into 24 squares
  • Store in an airtight container. Store well at room temp for 5 days. Freeze well.
Tried this recipe?Mention @HealthyGFFamily or tag #HealthyGFFamily!


12 thoughts on “Monster Cookies

  1. 5 stars
    These cookies are to die for! I have already baked them twice in three days! My mom said that they are the best cookies she has ever had… and she eats a lot of cookies!!!

    1. Yes, if you are not following a gluten-free diet, these should work fine with regular all purpose flour! They are based on my family’s peanut butter cookie which was not originally gluten-free. Let me know if you make them!

  2. 5 stars
    Oh My Gosh!! Those cookies! This recipe!
    simple easy to do soooo yummy …

    we made a bunch of those last week-end. it was a great mother-daughter time.
    she’s 8 and she’s just crazy about those monster cookies.

    we made few adaptation: grated coco instead of oats and french smarties candy instead of m&m’s.
    Peanut Butter was soooo mandatory 🙂

    thank you so much for sharing all those recipes.

  3. 5 stars
    I made these cookies for the first time today and they tasted amazing! My husband who usually isn’t a fan of gluten free cookies said he that he couldn’t even tell a difference! Win for me, means I don’t have to eat the whole batch myself? 10/10 recommend!

  4. Amazing!!! We love these cookies. My kids say they smell like peanut butter but don’t have an overwhelming taste of peanut butter. I had a bag of M&M baking chips to use and this was perfect. The softness of these is incredible. I have to stop eating them all!

  5. 5 stars
    LOVED this recipe! The didn’t stick around long in our house at all! I mean, peanut butter meets oatmeal m&m cookie? Genius! So glad my gfJules Flour was part of making this magic happen!

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