Gluten-Free Monster Cookie Bars

An easy, gluten-free bar cookie recipe for a fun, yummy and crowd-pleasing dessert! 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!

Gluten-free Monster Cookie Bars easy baking gluten-free dessert recipe
Gluten-Free Monster Cookie Bars

An easy, fun and crowd-pleasing gluten-free dessert!

This post may contain affiliate links. Please read our Disclaimer.

If you’re looking for the recipe for Monster Cookies, click here. For Monster Cookie Bars, read on!

So excited for you to try these Gluten-Free Monster Cookie Bars!

They are festive, fun and soooooo yummy! A total crowd-pleaser!

The texture is perfectly soft and chewy!

And they are EASY to make!

And you can make them with all different colors and brands of chocolate gems so that they fit any occasion — holidays, birthdays, any get together!

Gluten-free Monster Cookie Bars easy baking gluten-free dessert recipe

Back story: I have a recipe for Gluten-Free Monster Cookies that I shared a few years ago.

One of you in the Healthy Gluten-Free Community reached out and asked if they could be made into bar cookies.

Just like us, this person loves a good bar cookie because they are so quick and easy to whip up!

I said it was worth a try and gave a recommendation for size of pan, oven temperature and baking time. I also decided to try for myself.

They turned out fine. My taste testers and I all thought they tasted really good but personally I thought they were a little more cakey than I wanted in a bar cookie.

SO… I reworked the recipe a bit and the New Monster Cookie Bars are perfect!

How to Make Gluten-Free Monster Cookie Bars

All you need is ….

butter or dairy free butter

brown sugar

cane sugar

vanilla extract


peanut butter

gluten-free flour (we used GF Jules )

baking soda

gluten-free baking powder


gluten-free oats

chocolate chips

M&Ms (or a similar brand chocolate candies– we love to use Unreal Milk Chocolate Gems as well)

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!

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.

Step by Step How to Make Gluten-Free Monster Cookie Bars

They are super easy to whip up!

The batter comes together in 4 simple steps:

  1. 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.
  2. Then beat in the eggs and peanut butter.
  3. Add in the flour.
  4. Then the oats. Then stir in the chips and M&Ms.

Spoon into a 9×13 baking pan, top with extra m&ms and they are ready to bake!

The entire process takes 15 minutes or less!

Bake for just 25 minutes and enjoy!

The bars are soft & chewy, decadent tasting and soooo yummy!

They’ve been a huge hit with all our taste testers!

Gluten-free Monster Cookie Bars easy baking gluten-free dessert recipe



Hope you love them as much as we do!

For more crowd favorite bar cookies, try our:

Raspberry Crumble Bars

Better than Boxed Brownies

Gluten-Free Cheesecake Bars

Chocolate Peanut Butter No Bake Bars 

For more Monster Cookie Recipes, try our:

No Bake Monster Cookie Bites

PIN it!



Scroll down for recipe and leave a rating/ comment if you love them!.



Gluten-free Monster Cookie Bars easy baking gluten-free dessert recipe
Share on Facebook Pin Recipe Print Recipe Rate this Recipe
4.41 from 5 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 (or Unreal Chocolate Gems).
Switch up the color M&Ms or Unreal Chocolate Gems and make festive for any occasion, holiday or celebration.
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, gluten-free monster cookies
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,)
  • 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 (we love Unreal Milk Chocolate Gems too!) plus 1/2 cup more for topping


  • Preheat oven to 350 degrees F and line 9 x 13 baking with parchment paper, or grease the pan. 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!


4 thoughts on “Gluten-Free Monster Cookie Bars

  1. 5 stars
    These are incredible! I love monster cookies — but love these even more because of the simplicity of throwing the dough/batter in one baking pan and done! Will have to make another batch soon because our first batch is almost gone!

4.41 from 5 votes (4 ratings without comment)

Leave a Reply

Your email address will not be published. Required fields are marked *

Recipe Rating