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    Home » Cookies

    Monster Cookies

    By Elizabeth Waterson // Dec 20, 2019 (Updated Jun 9, 2025) // 2 Comments

    Jump to Recipe·Leave a Review
    This post may contain affiliate links, which may pay me a small commission for my referral at no extra cost to you! Thank you for supporting Confessions of a Baking Queen!

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    monster cookies on a white plate

    This easy recipe for monster cookies is perfect to whip up on a whim or with the kids. Full of oats, peanut butter, chocolate chips, and M&M's everyone loves these cookies. Step-by-step photos help you bake the perfect batch each time!

    plate full of monster cookies next to a cup of chocolate chip, oats, and m&ms and a spoon full of peanut butter

    It's that time of the year where eating copious amounts of cookies is encouraged. AKA my favorite time of the year. These monster cookies are a family favorite for the wonderful flavor and texture. Any dessert that has contrasting textures is a winner in my book, I die over my Dulce de Leche Napoleon for those reasons.

    The beauty of this recipe is there is no chilling time required, most of my cookie recipes do require a chill time. Chilling the cookie dough helps prevent the cookies from spreading. Because these cookies are full of oats and peanut butter there isn't a spreading issue.

    As with most cookie recipes, I bake half of the recipe and then freeze the rest for a cookie whenever I want. When I bake these from frozen or chilled I do find that I need to bang the pan on the floor halfway through baking to encourage the spreading. But just keep an eye on them, everyone's oven is different.

    Let's get to the monster cookie recipe.

    What are Monster Cookies

    Monster cookies are a peanut butter-based cookie chock a block full of oats/oatmeal, chocolate chips, and M&M's. These cookies have a great chewy texture and nice crunch thanks to the M&M's.

    monster cookie dough scooped into balls on a small baking sheet

    What are the ingredients

    You'll need your standard cookie ingredients here:

    • Unsalted Butter. Make sure your butter is completely softened to room temperature. Otherwise, it will not "cream" with the sugars properly.
    • Sugar. More light brown Sugar and less granulated sugar helps create a moist and chewy cookie.
    • Peanut Butter. You can use creamy or crunchy peanut butter here.
    • Large Egg. Your egg needs to be at room temperature, a quick way to warm it up is to place it in a bowl of warm water for 5 minutes.
    • Pure Vanilla Extract. Don't bother with the imitation stuff, it is nowhere near the real deal.
    • Oatmeal. A classic monster cookie has the chewy and texture of oats. I prefer to use quick-cooking oats but roller/old-fashioned oats work just as well.
    • All-Purpose Flour. We don't use a lot of flour here just enough to bind everything together. Some monster cookie recipes don't call for any flour but I prefer it in my cookies.
    • Baking Soda. To help raise the cookies and give them their lift.
    • Salt. Just a bit is needed in most dessert recipes, it really does help balance everything out.
    • M&Ms and Chocolate Chips. Two types of chocolate make these cookies extra special. I often use dark chocolate chips since the M&Ms are milk chocolate!!

    Instructions

    Preheat oven to 350F/180C and line a cookie sheet with a Silpat liner/ Silicone baking mat. In a large mixing bowl with a handheld electric whisk or in the bowl of an electric mixer beat butter and sugars for 2 minutes on medium speed.

    butter, brown sugar, and granulated sugar in a large mixing bowl

    Scrape down the sides of the bowl then add the peanut butter, mix for an additional one to two minutes.

    peanut butter added to sugar and butter mixture in a metal bowl

    Add in the egg and vanilla extract and mix until fully combined.

    peanut butter, egg, vanilla added to butter sugar mixture in a metal bowl

    In a medium bowl mix together oats, flour, baking soda, and salt.

    dry ingredients in a glass bowl for a monster cookie recipe

    Add dry ingredients, M&Ms, and chocolate chips to the wet ingredients and mix until just combined.

    m&ms, chocolate chips, and dry ingredients added to wet ingredients in a metal mixing bowl

    Be sure not to overmix the batter.

    monster cookie dough in a metal mixing bowl

    Use a medium cookie scoop and place on prepared baking sheet two inches apart. Add more M&M's and chocolate chips on top of each cookie, if desired.

    Bake for 8-11 minutes. Until golden brown and just set. Let cool on sheet for 5 minutes then transfer to wire rack. Store in an airtight container.

    tray of monster cookies just baked

    Can you freeze the cookies

    To freeze unbaked cookie dough:

    Scoop the cookie dough into the dough size you want then freeze on a flat surface lined with a silicone mat or parchment paper so they do not stick together. Once the dough is frozen, about 30-60 minutes you can move the cookie dough balls into a freezer-safe plastic bag or container.

    To bake frozen cookie dough balls:

    Just add an extra minute or two on the bake time. Rotate the pan halfway through, at this point if the cookies have not started to spread down then take the sheet out of the oven and bang on the floor once to encourage spreading. Immediately place the pan bake in the oven to continue baking.

    To freeze baked cookies:

    Once the cookies are baked let them cool on a wire rack until completely cooled. Place the cookies in a freezer-safe plastic bag or container. To thaw cookies let them sit at room temperature for 30 minutes.

    up close of monster cookie stood up against a plate of cookies

    Check out this post on my Cookie Baking Tips

    More cookie recipes

    If you're looking for a more basic M&M cookie check out my M&M Cookies Recipe.

    Or for a no bake cookie recipe check out my Chocolate Peanut Butter No Bake Cookies.

    Make sure to join our Newsletter and follow us on Pinterest, Instagram, Facebook, & Twitter.

    ★★★★★ Please let me know if you make this recipe by leaving a star rating and comment below!

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    plate full of monster cookies next to a cup of chocolate chip, oats, and m&ms and a spoon full of peanut butter

    Monster Cookies

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    This easy recipe for monster cookies is perfect to whip up on a whim or with the kids. Full of oats, peanut butter, chocolate chips, and M&M's everyone loves these cookies. Step-by-step photos help you bake the perfect batch each time!

    • Total Time: 20 minutes
    • Yield: 27 Cookies 1x

    Ingredients

    Units Scale
    • 4oz (½ cup) Unsalted Butter, at room temp.
    • 150 grams (¾ cup) Light Brown Sugar
    • 50 grams (¼ cup) Granulated Sugar
    • (4oz) ½ Cup Peanut Butter, creamy or crunchy
    • 1 Large Egg, at room temperature
    • 2 Teaspoons Pure Vanilla Extract
    • 100 grams (1 Cup) Quick Fashioned Oats
    • 125 grams (1 Cup) All-Purpose Flour
    • ½ Teaspoon Baking Soda
    • ½ Teaspoon Salt
    • 150 grams (¾ Cup) M&Ms
    • 90 grams (½ Cup) Chocolate Chips

    Instructions

    1. Preheat oven to 350F/180C and line a cookie sheet with a Silpat liner. In a large mixing bowl with a hand held electric whisk or in the bowl of an electric mixer beat butter and sugars for 2 minutes on medium speed.
    2. Scrape down the sides of the bowl then add the peanut butter, mix for an additional one to two minutes. Add in the egg and vanilla extract and mix until fully combined.
    3. In a medium bowl mix together oats, flour, baking soda, and salt. Add dry ingredients, M&M's, and chocolate chips to the wet ingredients and mix until just combined.
    4. Use a medium cookie scoop and place on prepared baking sheet two inches apart. Add more M&M's and chocolate chips on top of each cookie, if desired.
    5. Bake for 8-11 minutes. Until golden brown and just set. Let cool on sheet for 5 minutes then transfer to wire rack. Store in an airtight container for u pto 5 days.

    Equipment

    kitchen aid cordless hand mixer

    Cordless Hand Mixer

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    half sheet pans

    Half Sheet Pan

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    a medium cookie scoop on a plain white background

    Medium Cookie Scoop

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    silpat liner

    Silpat

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    oxo food scale

    OXO Kitchen Scale

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    • Author: Elizabeth Waterson I Confessions of a Baking Queen
    • Prep Time: 10
    • Cook Time: 10
    • Category: Dessert
    • Method: Bake
    • Cuisine: American

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    Tag @confessionsofabakingqueen on Instagram and hashtag it #cbqbakes

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    Comments

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      If you love this recipe, please consider leaving a ⭐ star rating ⭐ when you post a comment. Star ratings help people discover my recipes online. I am incredibly grateful for your support! —xx Liz

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    1. Brittni Davis says

      February 28, 2021 at 2:18 pm

      Going to make these today but I’m making for a large group. I hit x3 to adjust the recipe but the peanut butter measurement never changed. I’m guessing it’s 12 ounces but wanted to make sure. Also, if I’m using peanut butter m&ms instead of regular, should I use less peanut butter? & if I do that, should I use something else instead? I don’t want to mess the texture or consistency up.
      Thanks for helping a beginner out!

      Reply
      • Elizabeth Waterson says

        February 28, 2021 at 2:37 pm

        Hi Brittni, thanks for reaching out! Yes, you are right 12ounces I am so sorry it is not adjusting, I am not sure why, I am going to reach out to support to try and fix it! I wouldn't alter the peanut butter amount if you are using PB m&ms because I love peanut butter! If you wanted just a plain cookie to use with M&MS you could try my M&M cookie recipe! Let me know if I can help with anything else, feel free to DM me on Instagram as I Am quicker to reply there and you can send photos if you have questions! And do report back how you like the cookies! Goodluck! XX Liz

        Reply

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    Hiya! I am Elizabeth Waterson, welcome to my treat-filled site. After spending 15 years in the restaurant industry and growing up baking, I wanted to share my love of baking with you all. My step-by-step tutorials will help you learn how to bake at home. Confessions of a Baking Queen (CBQ) has been featured in CBS LA, HuffPost Taste, BuzzFeed, Taste of Home, and more! Here you will find loads of sweet recipes with a few savory ones for good measure. Feel free to message me with any questions! Happy Baking! 

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