Gluten-Free Monster Cookie Bars (Dairy-Free Option)
Chewy and studded with colorful M&M’s, these gluten-free monster cookie bars are a delicious sweet treat for the whole family! Go bake a batch or two to enjoy today!
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Fun Monster Cookie Bars!
Cookie bars are an easy way of making cookies (without having to roll out the dough!). I mean, just press the cookie dough into the baking dish, and then bake directly before cooling and slicing.
These monster cookie bars are basically regular cookie bars studded with M&M candies and chocolate chips, making them a decadent snack that chocolate lovers will love!
Why This Recipe Works:
- Simple Ingredients: The main ingredients you need for these gluten free monster cookie bars are easily accessible at the local grocery store (nothing fancy required!).
- Easy to Make: Preparing these gf monster bar cookies is just a matter of mixing the dry ingredients with the wet ingredients to get the cookie dough, before folding in the M&Ms and chocolate chips. Then transfer the dough to a baking dish and bake, cool and slice into bars!
- Totally Gluten-Free (with Dairy-Free Option): The best part is that this easy monster cookie bar recipe are 100% gluten-free, with the option of making them dairy-free too. This means that even those with Celiac disease or gluten or lactose intolerances can enjoy them without issues!
Ingredients You’ll Need:
Here’s a visual overview of the ingredients you’ll need for this gluten-free monster cookie bars recipe.
(For exact measurements, please scroll down to the printable recipe card at the bottom of this post.)
Recipe Notes + Substitutions
- Gluten-Free Flour: Make sure to use a good-quality gluten-free measure-for-measure flour (a 1:1 gluten-free substitute for regular all-purpose flour) that is made up of lighter flours/starches (such as rice flour, tapioca starch, corn starch or potato starch). I do NOT recommend using a gluten-free flour blend that is made up of heavier flours (such as garbanzo bean flour).
- Xanthan Gum: Xanthan gum is the replacement for gluten in gluten-free flours, and helps the ingredients better bind together. If your gluten-free flour blend does not already include xanthan gum, make sure to add it in.
- Cornstarch: If you are allergic to cornstarch, you may also use tapioca starch or arrowroot starch instead.
- Leavening Agents: I used both baking soda and baking powder as leavening agents. If you are Celiac or gluten-intolerant, make sure to use gluten-free baking soda and gluten-free baking powder.
- Butter: Make sure to use unsalted butter since we are already adding salt. Brown the butter in a skillet over medium high heat, melting it and then cooking it until caramelized and brown. If you are lactose-intolerant, feel free to use unsalted dairy-free butter instead.
- Brown Sugar: I used dark brown sugar, but light brown sugar or coconut sugar will work just as well. If you are diabetic or insulin-resistant, I highly recommend using brown granulated monkfruit sweetener (a 1:1 brown sugar substitute that is zero glycemic index and will not raise your blood sugar).
- Sugar: I used white sugar, but cane sugar will work just as well. If you are diabetic or insulin-resistant, I highly recommend using granulated monkfruit sweetener (a 1:1 sugar substitute that is zero glycemic index and will not raise your blood sugar).
- Eggs: Eggs help to bind the ingredients together as well as give these gluten-free monster cookie bars a chewy texture, so make sure to add them in.
- Vanilla Extract: I like adding vanilla extract for extra flavor, but you if you don’t like vanilla, feel free to leave it out.
- Mini M&M’s: Colorful M&M’s are a key ingredient in monster cookies, so make to add them in. We’re using mini M&M’s here, but you can also use regular-sized M&Ms if you prefer. (Most M&M’s made in the US are gluten-free except for the flavors such as pretzel and crispy M&M’s). If you are lactose-intolerant, here’s a dairy-free version you can use.
- Semisweet Chocolate Chips: I like adding semisweet chocolate chips for an extra chocolate-y flavor. If you are lactose-intolerant, you can use these dairy-free chocolate chips too. However, feel free to leave them out if you prefer.
How to Make Gluten-Free Monster Cookie Bars (Step by Step):
1. Preheat and Line
Preheat the oven to 350F. Line a large baking dish with parchment paper.
2. Sift Dry Ingredients
In a large mixing bowl, sift together the gluten-free measure-for-measure flour, cornstarch, baking powder, baking soda and salt. Set aside.
3. Whisk Butter and Sugar
In a smaller bowl, add the slightly cooled browned butter, brown sugar and white sugar. Whisk together until combined.
4. Add Eggs and Vanilla
Then add the eggs and vanilla. Whisk again until smooth.
5. Combine Wet and Dry Ingredients to Get Dough
Pour the wet ingredients into the large bowl with the dry ingredients and mix together with a rubber spatula until well combined. The dough should be thick.
6. Fold in Chocolate Chips and M&Ms
Add the chocolate chips and mini M&M’s. Fold into the dough until evenly distributed.
7. Transfer Dough to Baking Dish
Transfer the cookie dough into the prepared baking dish, pressing it and spreading it out into an even layer.
8. Bake Until Ready
Bake in the oven for about 24 minutes or until the top has become crusted.
9. Top with More M&M’s
As soon as you remove from the oven, top with extra mini M&M’s and slightly press into the top of the warm cookie bars.
10. Cool Before Slicing
Let cool for at least 15 minutes before cutting into squares and serving these dessert bars!
Dish by Dish Tips/Tricks:
- Storing: To store, place the gluten-free M&M cookie bars in an airtight container or wrap tightly with plastic wrap and store these chewy bars at room temperature for up to 3 days.
- Optional Add-Ins: If you like, you can substitute the dark chocolate chips with peanut butter chips, as well as add in certified gluten-free quick oats or rolled oats.
Other Gluten-Free Cookie Bars You’ll Enjoy:
- Chocolate Chip Cookie Bars (Gluten-Free, Dairy-Free)
- Moist Banana Bars (Gluten-Free, Dairy-Free)
- Easy Lemon Bars (Gluten-Free, Dairy-Free)
- Pumpkin Bars (Gluten-Free, Dairy-Free)
Gluten-Free Cookies to Make:
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Gluten-Free Monster Cookie Bars
- Total Time: 35 minutes
- Yield: 24 cookie bars 1x
- Diet: Gluten Free
Description
Chewy and studded with colorful M&M’s, these gluten-free monster cookie bars are a delicious sweet treat for the whole family! Go bake a batch or two to enjoy today!
Ingredients
- 2 1/2 cup gluten-free measure-for-measure flour
- 3/4 teaspoons xanthan gum
- 1 1/2 teaspoons cornstarch
- 1 teaspoon baking soda
- 1/4 teaspoon baking powder
- 1/2 teaspoon salt
- 1 cup unsalted butter, browned
- 1 cup brown sugar
- 1/2 cup white granulated sugar
- 2 eggs
- 2 teaspoons vanilla extract
- 1 1/2 cups mini M&M’s + more for topping
- 1/2 cup semisweet chocolate chips
Instructions
- Preheat and Line: Preheat the oven to 350F. Line a large baking dish with parchment paper.
- Sift Dry Ingredients: In a large mixing bowl, sift together the gluten-free measure-for-measure flour, cornstarch, baking powder, baking soda and salt. Set aside.
- Whisk Butter and Sugar: In a smaller bowl, add the slightly cooled browned butter, brown sugar and white sugar. Whisk together until combined.
- Add Eggs and Vanilla: Then add the eggs and vanilla. Whisk again until smooth.
- Combine Wet and Dry Ingredients to Get Dough: Pour the wet ingredients into the dry and fold together with a rubber spatula until well combined. The dough should be thick.
- Fold in Chocolate Chips and M&M’s: Add the chocolate chips and mini M&M’s. Fold into the dough until evenly distributed.
- Transfer Dough to Baking Dish: Transfer the dough into the prepared baking dish. Press into the dish, spreading evenly.
- Bake Until Ready: Bake in the oven for about 24 minutes or until the top has become crusted.
- Top with More M&M’s: As soon as you remove from the oven, top with extra mini M&M’s and slightly press into the top of the warm cookie bars.
- Cool Before Slicing: Let cool for at least 15 minutes. before cutting into squares and serving!
Notes
Gluten-Free Flour: Make sure to use a good-quality gluten-free measure-for-measure flour (a 1:1 gluten-free substitute for regular all-purpose flour) that is made up of lighter flours/starches (such as rice flour, tapioca starch, corn starch or potato starch). I do NOT recommend using a gluten-free flour blend that is made up of heavier flours (such as garbanzo bean flour).
Xanthan Gum: Xanthan gum is the replacement for gluten in gluten-free flours, and helps the ingredients better bind together. If your gluten-free flour blend does not already include xanthan gum, make sure to add it in.
Cornstarch: If you are allergic to cornstarch, you may also use tapioca starch or arrowroot starch instead.
Leavening Agents: I used both baking soda and baking powder as leavening agents. If you are Celiac or gluten-intolerant, make sure to use gluten-free baking soda and gluten-free baking powder.
Butter: Make sure to use unsalted butter since we are already adding salt. Brown the butter in a skillet over medium high heat, melting it and then cooking it until caramelized and brown. If you are lactose-intolerant, feel free to use unsalted dairy-free butter instead.
Brown Sugar: I used dark brown sugar, but light brown sugar or coconut sugar will work just as well. If you are diabetic or insulin-resistant, I highly recommend using brown granulated monkfruit sweetener (a 1:1 brown sugar substitute that is zero glycemic index and will not raise your blood sugar).
Sugar: I used white sugar, but cane sugar will work just as well. If you are diabetic or insulin-resistant, I highly recommend using granulated monkfruit sweetener (a 1:1 sugar substitute that is zero glycemic index and will not raise your blood sugar).
Eggs: Eggs help to bind the ingredients together as well as give these gluten-free monster cookie bars a chewy texture, so make sure to add them in.
Vanilla Extract: I like adding vanilla extract for extra flavor, but you if you don’t like vanilla, feel free to leave it out.
Mini M&M’s: Colorful M&M’s are a key ingredient in monster cookies, so make to add them in. We’re using mini M&M’s here, but you can also use regular-sized M&Ms if you prefer. (Most M&M’s made in the US are gluten-free except for the flavors such as pretzel and crispy M&M’s). If you are lactose-intolerant, here’s a dairy-free version you can use.
Semisweet Chocolate Chips: I like adding semisweet chocolate chips for an extra chocolate-y flavor. If you are lactose-intolerant, you can use these dairy-free chocolate chips too. However, feel free to leave them out if you prefer.
Storing: To store, place the gluten-free M&M cookie bars in an airtight container and store at room temperature for up to 3 days.
- Prep Time: 10 mins
- Cook Time: 25 mins
- Category: Cookies
- Method: Baking
- Cuisine: American




I love making these monster cookie bars which can be ready in a very short time especially when one is in a hurry to make them for children to share with their friends.
Children love them too as they are so colorful and taste great!
Perfect cookies for children indeed!!