Irresistible Gluten-Free Monster Cookie Bars: Your New Go-To Dessert

Prepare to fall in love with our Gluten-Free Monster Cookie Bars! This recipe captures everything delightful about classic monster cookies and transforms it into a convenient, crowd-pleasing bar format. Imagine a lusciously soft and chewy peanut butter oatmeal cookie base, generously studded with vibrant M&Ms and rich chocolate chips in every single bite. These bars are not just a treat; they’re an experience, offering a burst of flavor and a comforting texture that will have everyone asking for more.

Perfect for bake sales, parties, or simply satisfying that sweet tooth, these monster cookie bars eliminate the fuss of individual cookie scooping and rolling. They offer an effortless baking experience without compromising on the nostalgic taste and vibrant appearance that make monster cookies so beloved. Get ready to bake a batch of pure joy!

Why You’ll Adore These Easy-to-Make Gluten-Free Cookie Bars

If you’re already a devotee of traditional monster cookies, prepare for a new obsession! These delightful monster cookie bars capture the exact soft, chewy texture and irresistible flavor you crave, but with an added layer of simplicity. They are designed for maximum enjoyment with minimum effort, making them a fantastic option for busy bakers and dessert enthusiasts alike.

• Unbeatable Ease: One of the standout features of these cookie bars is their sheer simplicity. Unlike individual cookies that require scooping and shaping, these bars are a “press and bake” affair. You simply mix the dough, spread it evenly into a pan, bake until golden, and then garnish. No complicated techniques or fussy ingredients to source – just pure, straightforward baking enjoyment! This makes them perfect for beginner bakers or anyone looking for a stress-free dessert.
• Explosive Flavors: Every bite is a symphony of classic monster cookie flavors. The rich, nutty peanut butter forms the backbone, beautifully complemented by the sweet intensity of chocolate chips and M&Ms. A hint of vanilla adds warmth and depth, while a touch of salt perfectly balances the sweetness, creating a truly harmonious flavor profile. It’s a combination that truly tastes “SO GOOD” and leaves a lasting impression.
• Perfect Texture Every Time: Achieving that ideal soft, chewy, and slightly fudgy consistency is key, and this recipe delivers. The blend of sugars and the thoughtful addition of an extra egg yolk contribute to an incredibly tender crumb. The most crucial tip for this perfect texture? Avoid overbaking! The bars will continue to set as they cool, ensuring they remain wonderfully moist and soft.

Happy baking, and enjoy every delicious moment! xo, Emily

Essential Ingredients for Your Gluten-Free Monster Cookie Bars

One of the many reasons this easy recipe is such a hit and a definite crowd-pleaser is its straightforward ingredient list. Let’s dive into the components that make these monster cookie bars so special and flavorful:

• Gluten-Free Flour: The foundation of our gluten-free baking! We highly recommend King Arthur Measure For Measure Gluten-Free Flour for its consistent results. If you opt for another 1:1 gluten-free flour blend, ensure it contains xanthan gum to provide structure and prevent crumbly bars. For the most accurate and best results, weighing your flour (and other dry ingredients) with a kitchen scale is ideal. If a scale isn’t available, use the scoop and level method to avoid compacting too much flour into your measuring cup, which can lead to dry bars.
• Gluten-Free Oats: For an optimal texture that’s both chewy and substantial, we prefer a delightful combination of gluten-free rolled oats (also known as old-fashioned oats) and gluten-free quick oats. It adds a lovely depth and chewiness. Always double-check that your oats are certified gluten-free to ensure they are safe for those with celiac disease or gluten sensitivities.
• Baking Soda & Kosher Salt: These aren’t just minor additions; they’re crucial for the perfect spread, rise, and flavor balance of your cookie bars. Baking soda helps achieve a soft, tender crumb, while kosher salt enhances all the sweet and savory notes, preventing the bars from tasting overly sweet.
• Butter: For the best creaming results and a truly tender texture, ensure your butter is softened to room temperature. You can use either salted or unsalted butter in this recipe; we typically use salted butter for an added layer of flavor balance.
• Granulated Sugar & Brown Sugar: The magic happens with a blend of both! Light brown sugar contributes to a wonderfully soft and moist texture, thanks to its molasses content, while granulated white sugar ensures a classic cookie sweetness and helps with spread. This combination is essential for the perfect chewy consistency.
• Creamy Peanut Butter: The star of monster cookies! We highly recommend using a traditional creamy peanut butter spread, such as JIF or Skippy. Avoid natural peanut butter (the kind that separates) for this recipe, as its oil content can alter the dough’s consistency and lead to drier, less tender cookie bars that can dry out faster.
• Eggs & An Egg Yolk: To achieve that irresistible fudgy texture and bind everything together, this recipe calls for two large eggs plus an additional egg yolk. The extra yolk adds richness and fat, contributing to a more dense and chewy bar. If you’re new to it, here’s how to separate an egg easily! Please note, we haven’t tested this recipe with egg substitutes like chia or flax eggs.
• Vanilla Extract: A generous amount of pure vanilla extract is essential. It beautifully complements the rich peanut butter and chocolate flavors, adding a warm, aromatic note that elevates the overall taste.
• Chocolate Chips & Mini Chocolate Chips: For the ultimate chocolate experience, we use a mix! Semi-sweet or dark chocolate chips are our preference, as they provide a deeper, richer chocolate flavor that balances the inherent sweetness of the cookie base and M&Ms. Using a combination of regular and mini chips ensures chocolate in every bite.
• Mini M&Ms: Here’s a unique twist that sets our recipe apart! We love using mini M&M candies instead of regular milk chocolate M&Ms. The smaller size means they blend more seamlessly into the dough, are easier to cut through once baked, and frankly, they just look adorable with their vibrant, cheerful colors!

Step-by-Step Guide: Crafting Your Gluten-Free Monster Cookie Bars

Creating these delightful cookie bars is simpler than you might think. Follow these detailed steps to ensure perfectly soft, chewy, and flavorful monster cookie bars every single time. As always, for exact ingredient amounts and a printable version, refer to the recipe card at the bottom of this post.

1. Preheat Oven & Prepare Your Pan: Begin by preheating your oven to 350 degrees F (175 degrees C). Line a standard metal 9×13 inch baking pan with parchment paper, allowing some overhang on the sides. This “sling” will make it incredibly easy to lift the baked bars out of the pan for neat slicing. Set the prepared pan aside.
2. Combine Dry Ingredients: In a medium-sized mixing bowl, whisk together the gluten-free flour blend, gluten-free rolled oats, gluten-free quick oats, baking soda, and kosher salt. Whisk thoroughly until all ingredients are evenly blended and the mixture appears light and fluffy. This ensures even distribution of leavening and seasoning. Set this bowl aside.
3. Cream Butter & Sugars: In the bowl of a stand mixer fitted with the paddle attachment (or using a large mixing bowl and a handheld electric mixer), combine the softened butter, light brown sugar, and granulated sugar. Beat on medium speed for 2-3 minutes. Continue mixing until the butter and sugar mixture becomes noticeably light, fluffy, and creamy. This process incorporates air, which contributes to the soft texture of the bars. Don’t forget to scrape down the sides of the bowl midway through to ensure everything is well combined.
4. Build The Dough Base: Add the creamy peanut butter to the butter and sugar mixture and beat until it is fully incorporated and smooth. Next, add the large eggs, one at a time, mixing well after each addition. Follow with the extra egg yolk and the vanilla extract, beating until just combined. Scrape down the sides of the bowl one more time to ensure no ingredients are sticking. Finally, gradually add the reserved dry ingredients to the wet mixture, mixing on low speed until just a few dry patches of flour remain. Be careful not to overmix, as this can develop the gluten-free flour too much and result in tough bars.

5. Fold in the Mix-Ins: Now for the fun part! Add 1 1/4 cups of mini M&Ms and 1 1/4 cups of semi-sweet chocolate chips to the dough. Using a sturdy spatula, gently stir these mix-ins by hand. This manual folding prevents the M&Ms from breaking and ensures they are well distributed throughout the dough without overworking it. Continue until the dough is uniformly blended with all the colorful goodies.
6. Bake to Perfection: Transfer the cookie dough into your prepared 9×13 inch pan. Use an offset spatula or the back of a spoon to spread the dough out into an even layer, pressing it gently into all corners of the pan. Bake for 25-30 minutes, or until the cookie bars appear golden brown around the edges and are just set in the center. The center might look slightly soft, but that’s what we want for a fudgy interior! It’s crucial not to overbake; otherwise, your bars will turn out dry and cakey instead of soft and chewy. Remember, the bars will continue to cook and firm up as they cool on the counter.
7. Immediately Add Toppings: As soon as the cookie bars emerge from the hot oven, generously sprinkle the extra 1/4 cup of mini M&Ms and 1/4 cup of mini chocolate chips over the warm surface. The residual heat will slightly melt the chocolate, helping the toppings adhere beautifully. This step adds visual appeal and an extra burst of flavor and texture.
8. Cool, Cut, & Store: Place the baking pan on a wire rack and allow the cookie bars to cool completely before attempting to slice them. This patience is key! Cooling allows the bars to fully set, ensuring clean, neat slices. For the absolute neatest cuts, you can even chill the cookie bars in the refrigerator for about 30 minutes to an hour before slicing. Once cooled and cut, serve and enjoy! Store any leftover cookie bars in an airtight container at room temperature for 2-3 days, or freeze them for up to 2 months for a longer shelf life.

Pro Tips & Frequently Asked Questions for Perfect Monster Cookie Bars

To ensure your gluten-free monster cookie bars turn out absolutely perfect every time, consider these expert tips and answers to common questions:

• Does Your Pan Material Matter? Absolutely! The type of baking pan you use can significantly impact your bake. Metal pans conduct heat gently and evenly, resulting in a beautifully consistent bake and a perfect thickness for these bars. If you opt for a glass or ceramic baking dish, be aware that these materials retain heat differently. You’ll likely need to add a few extra minutes to the bake time, and you might notice the edges “climbing” or setting faster than the center. For this recipe, we highly recommend a sturdy metal 9×13 inch pan for optimal results.
• Can I Substitute Natural Peanut Butter? While natural peanut butter is fantastic for many applications like sandwiches and oatmeal, we generally do not recommend it for these monster cookie bars. Natural peanut butter tends to have a different oil content and consistency compared to traditional creamy spreads (like JIF or Skippy). Using it can make your cookie bars dry out faster and may negatively impact their desired soft, chewy texture. Stick to the classic, emulsified creamy peanut butter for the best outcome!
• Making Them Dairy-Free? Yes, these delicious monster cookie bars can easily be adapted to be dairy-free with just a few simple swaps. First, replace regular butter with a high-quality vegan butter substitute (brands like Earth Balance often work wonderfully). Next, ensure you use dairy-free chocolate chips (Guittard or Enjoy Life are excellent choices). Finally, for the colorful touch, substitute traditional M&Ms with dairy-free chocolate candies. We’ve had great success with YumEarth Choco Yums and Unreal Candies, which offer similar vibrant colors and delicious taste.
• Creative Mix-In Ideas? Don’t be afraid to customize your monster cookie bars! While the classic M&Ms and chocolate chips are phenomenal, you can easily experiment with other goodies. Next time you’re looking to change things up, try swapping half of the chocolate chips for peanut butter chips to amplify that nutty flavor. Another popular option is to replace the M&Ms with Reese’s Pieces for an extra burst of peanut butter candy goodness. The possibilities are endless for making these bars uniquely yours!

Explore More Gluten-Free Cookie Bar Creations

If you’ve loved these Gluten-Free Monster Cookie Bars, you’re in for a treat! We have a delightful collection of other gluten-free cookie bar recipes that are equally simple to make and incredibly delicious. Perfect for any occasion or just to satisfy a craving, these recipes are designed to bring joy to your kitchen.

Gluten-Free S’mores Bars

View Recipe

Gluten-Free Oatmeal Fudge Bars

View Recipe

Gluten-Free Sugar Cookie Bars

View Recipe

Gluten-Free Brookies

View Recipe

Gluten-Free Monster Cookie Bars

5 from 1 vote

Author:
Emily Dixon, Sweets & Thank You

Our Gluten-Free Monster Cookie Bars recipe is everything you love about classic monster cookies in bar form! Made with a soft peanut butter oatmeal cookie base, they’re packed with m&ms and chocolate chips in every delicious bite!

Prep Time:
20 minutes minutes

Cook Time:
30 minutes minutes

Total Time:
50 minutes minutes

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Servings:
20 Cookie Bars

Ingredients

Dry Ingredients:

• 1 ¾ cup gluten-free measure-for-measure flour* (210 grams)
• 1 cup gluten-free rolled oats (or more quick oats)*
• ½ cup gluten-free quick oats (or more rolled oats)*
• 1 teaspoon baking soda
• ½ teaspoon kosher salt

Wet Ingredients:

• 1 cup butter, softened (226 grams)
• 1 ¼ cup light brown sugar (250 grams)
• ⅓ cup granulated sugar (66 grams)
• 1 cup creamy peanut butter*
• 2 large eggs room temperature
• 1 egg yolk room temperature
• 1 Tablespoon vanilla extract

Mix-Ins & Toppings:

• 1 ¼ cups mini M&Ms for the cookie dough
• 1 ¼ cups semisweet chocolate chips for the cookie dough
• ¼ cup mini M&Ms for topping the cookies
• ¼ cup mini chocolate chips for topping the cookies

Instructions

• Preheat & Prep. To Start, preheat oven temperature to 350 degrees F. Line a metal 9×13 pan with parchment paper and set aside.
• Combine Dry Ingredients. In a medium bowl, combine gluten-free flour, gluten-free oats, quick oats, baking soda, and salt. Whisk to combine until evenly blended and fluffy. Set aside.
• Cream Butter & Sugar. In a stand mixer (or large mixing bowl), combine softened butter, brown sugar, and granulated sugar. Beat on medium speed 2-3 minutes with the paddle attachment (or a handheld electric mixer) until the mixture is light, fluffy, and creamy. Scrape down the sides of the bowl.
• Build The Dough. Mix in the peanut butter until fully incorporated. Add eggs, one at a time, followed by the egg yolk, and the vanilla. Scrape down the sides of the bowl. Add the dry ingredients, and mix until just a few dry patches remain.
• Add Mix-Ins. Then, add 1 1/4 cups mini M&Ms, and 1 1/4 cups chocolate chips to the dough. Stir the mix-ins in by hand with a spatula (so you don’t break the M&Ms), until the dough is well blended and the goodies are well distributed.
• Bake Cookies. Spread cookie dough out into the prepared pan and smooth into an even layer with an offset spatula. Bake 25-30 minutes, or until the cookie bars look golden brown on top and just set in the center. (Try not to overbake, or the bars will be dry and cakey rather than fudgy and soft. Keep in mind that the cookie bars will continue to bake and set as they cool.)
• Immediately Add Topping. As soon as the cookie bars come out of the oven, sprinkle the extra mini M&Ms and the mini chocolate chips on top while they cookie bars are still hot from the oven. Place the pan on a wire rack and let cookie bars cool completely before slicing. (Chilling the cookie bars first will give you the neatest slices!)
• Serve & Store. When cookie bars have cooled completely, cut into slices & enjoy! Store leftover cookies in an airtight container at room temperature 2-3 days, or freeze up to 2 months.

Notes

• Gluten-Free Flour. We love and recommend King Arthur Measure For Measure Gluten-Free Flour for these monster cookie bars. If you use another 1:1 gluten-free flour blend, be sure it contains xanthan gum! We highly recommend weighing the flour (and other dry ingredients) for the best results, but if you don’t have a kitchen scale, we recommend using the scoop and level method to avoid packing too much flour into the measuring cup.
• Peanut Butter. Do NOT use natural peanut butter for these cookie bars, or they’ll dry out faster. Use a traditional peanut butter spread, like JIF or Skippy, for best results.
• Oats. If needed, you can use all rolled oats or all quick oats for these cookies. I just love the texture you get from using a mix!
• Toppings: I love the look of mini m&ms and mini chocolate chips on top of the cookie bars. You can use traditional M&Ms and chocolate chips, though your cookie bars will look different from mine.

Video

Course:
Dessert

Cuisine:
American

Diet:
Gluten Free

Keyword:
gluten-free monster cookies, monster cookie recipe

Find the recipe:

sweetsandthankyou.com/monster-cookie-bars/