Gluten-Free Monster Cookies

Chewy in the middle, crisp on the edges, and packed with rich peanut butter and melty M&Ms—these gluten-free monster cookies skip the gluten-free flour blends and still deliver structure thanks to oat flour. Tested multiple times for foolproof results, this is our extra-monster, double-peanut version that doesn’t fall apart, even when baked from frozen.

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✋🏼E aí, pessoal! Hey there, friends!

If you’re new here, welcome! I’m Patricia, a Brazilian-born mom of three living in Toronto. For over a decade, I’ve specialized in creating gluten-free recipes that are reliable, stress-free, and delicious enough to keep my mixed-diet family happy (yes, even my pickiest eaters!).

When my son first went gluten-free, we faced constant baking struggles—crumbly cookies, gritty textures, and too many complicated flour blends. I quickly learned that the easiest path to baking success was using ingredients naturally designed for gluten-free cooking. Our Almond Cinnamon Cookies were one of our first wins—easy, tasty, and zero frustration.

Today we’re sharing a family favorite inspired by that success: Gluten-Free Monster Cookies. They're chewy in the center, crisp on the edges, loaded with peanut butter, mini M&Ms for better candy distribution, and crunchy peanuts without extra sugar. No specialty flours, no guessing games—just simple oats and pantry ingredients you probably already have. Plus, they're freezer-friendly, so baking them fresh is always stress-free, even on your busiest days.

Looking for more easy gluten-free treats? Check out our Gluten-Free Rice Krispie Treats or Brazilian Cajuzinho (Peanut Truffles)—both kid-approved and perfect for beginners!

🍪Ingredient Notes

This gluten-free monster cookies recipe brings together pantry staples and a few fun mix-ins to make a chewy, peanut buttery cookie that hits that “kitchen sink” vibe in the best way. Here’s what we use and why:

👉 Want to skip ahead? Jump to the Recipe

• Creamy Peanut Butter: I went with creamy peanut butter for that classic cookie texture and rich peanut butter flavor. Make sure it’s gluten-free, and if you’re using natural peanut butter, stir it well to avoid oily spots in the dough.
• Room Temperature Butter: Using butter at room temperature helps it cream better with the sugars, giving us that soft, chewy texture. You can use vegan butter to make this dairy-free—I'll cover that below.
• Granulated Sugar + Brown Sugar: I like using both. The granulated sugar gives the monster cookies structure and helps the edges turn golden brown, while the brown sugar adds moisture and that deeper, almost caramel-like flavor that makes a chewy cookie so good.
• Large Eggs: The eggs bind everything together and help the cookies puff slightly. They’re important for structure and richness.
• Quick Cooking Oats + Oat Flour: Most monster cookie recipes just use oats, but I add in a little oat flour (simply blend your quick oats in a food processor or blender). In testing this recipe, adding oar flour gave our cookies more structure without needing traditional flour.
• Vanilla Extract: Just a splash brings out the warm flavors of the oats, peanut butter, and chocolate. Don’t skip it.
• Baking Soda + Salt: A little baking soda gives the monster cookies a slight lift, and the salt balances all the sweetness. Small but important. Make sure to check you use certified gluten-free baking soda (that is a sneaky place for cross-contamination).
• Mini M&Ms: Unlike other recipes, I like to use the mini M&Ms! They add crunch, color, and a fun candy bite. I like using mini M&Ms over regular ones because they spread out better in each bite—and kids love the smaller size.
• Chopped Peanuts: For crunch and an extra peanuty bite. They’re optional, but I like the extra texture.

Quantities and full instructions are in the recipe card at the bottom of the post.

⚠️ Gluten & Celiac Safety Alert: If you’re baking for someone with celiac disease, double-check that your oats, peanut butter, and chocolate candies (like M&Ms) are certified gluten-free. Cross-contamination is common in those ingredients, so it's worth the extra label check. M&Ms aren’t officially certified, and cross-contamination is possible even if no gluten ingredients are listed.

👩🏽‍🍳How to Make Flourless, Gluten-Free Monster Cookies

Step 1: Preheat and Prep

Preheat your oven to 350°F (180°C). Line a baking sheet or cookie sheet with parchment paper so the cookies don’t stick. Set out a wire rack for cooling later.

📌 Tip: If your kitchen runs cold, let your butter sit out a little longer so it’s truly at room temperature—this helps everything mix smoothly.

Step 2: Crem Butter and Sugar

In a large bowl or stand mixer fitted with the paddle attachment, combine butter, granulated sugar, and brown sugar. Mix on medium speed until smooth and fluffy—this takes about 2–3 minutes.

Step 3: Add Wet Ingredients

Add in the eggs, peanut butter, and vanilla extract. Mix until everything is fully combined and the mixture looks creamy. If your peanut butter is cold or too thick, you may need to mix a little longer.

Step 4: Add Dry Ingredients

In a separate small bowl, mix together the oat flour, quick oats, baking soda, and salt. Stir well to combine. Then add the dry mixture to the bowl with the wet ingredients and mix until everything is fully incorporated.

📌 Tip: Mixing the dry ingredients separately first helps distribute the baking soda evenly so you don’t end up with bitter bites.

Step 5: Mix In The Fun Stuff

Fold in the mini M&Ms and chopped peanuts. The dough will be thick but should hold together well. If it feels too soft, you can chill it for 10–15 minutes to make it easier to scoop.

Step 6: Scope Dough

Use a large cookie scoop (about 2 tablespoons) or a tablespoon cookie scoop for smaller cookies. Roll the dough into cookie dough balls and place them on your prepared baking sheet, leaving a couple inches between each one—they’ll spread as they bake.

Once they’re on the tray, press a few extra mini M&Ms and chopped peanuts on top of each cookie. It makes them look more fun and helps that “monster cookie” vibe really pop.

Step 7: Flatten and Bake Monster Cookies

Use a flat-bottomed glass, your hands, or a spatula to gently press down on each monster cookie dough ball, flattening them slightly. Bake for 10–12 minutes, or until the edges are golden brown and the centers still look soft.

📌 Tip: For best results and a chewier cookie, pull them out while the middle still looks slightly underbaked. They’ll finish setting up as they cool.

💡My Best Tips for Monster Cookies

Here’s what’s worked best for me when making these gluten-free monster cookies at home with my own busy crew:

• Don’t skip the oat flour: Most monster cookie recipes just use oats, but a bit of oat flour gives the dough better structure—especially helpful when you’re baking without gluten.
• Room temp butter = better texture: Cold butter won’t cream properly and will throw off the final texture. Let it soften on the counter instead of rushing it in the microwave.
• Flatten the monster cookies before baking: These don’t spread a ton on their own. Use your hand, a spatula, or a flat-bottomed glass to gently press them down before they go in the oven.
• For smaller monster cookies, shave off a couple of baking minutes: If you’re using a smaller scoop or making bite-sized cookies, reduce the baking time by 1–2 minutes to avoid overbaking.
• Chill the dough if it’s warm: This is especially helpful if your kitchen is warm or your peanut butter is runny. A short chill helps the dough hold its shape.

🍴Serving Suggestions

These gluten-free monster cookies are pretty versatile—here’s how we’ve been serving them at home (and a few ways to make them stretch a little further):

• After-school snack: Pair with fresh fruit or a glass of dairy-free milk. They’re sweet, filling, and hit that treat-but-not-junk vibe.
• Birthday party dessert: Stack them up with other gluten-free cookies or our gluten-free rice krispie treats, or serve with cut fruit for an easy party tray.
• Freezer stash: These freeze well, so I like keeping extras on hand for playdates, bake sales, or surprise guests.
• Make it a cookie sandwich: Add some ice cream between two monster cookies for a fun weekend treat.
• Gift it: These monster cookies hold up great in a box or bag. Wrap a few in parchment and tie with string for a quick homemade gift or thank-you.

🥣More Gluten-Free Treats

Looking for more gluten-free desserts that actually work for the whole family? Try these next:

👋🏼 Até logo, amigos! Hope you love these gluten-free monster cookies as much as we do. Comment below on what you would add to your monster cookies to make them your own. Até a próxima! 🎉