Monster Cookies

from 324 votes

Preheat your oven for a classic flourless Monster Cookies recipe that’s been in my family for more than two decades.

Monster Cookies studded with mini chocolate chips and M&Ms

Chocolatey, chewy, peanut buttery goodness. There’s no better way to describe this tried and tested family recipe for Monster Cookies.

My mom got this recipe from a friend more than 25 years ago, and it’d be impossible to count just how many dozens of Monster Cookies have been baked and enjoyed since that glorious recipe exchange.

Stand mixer bowl with monster cookies batter, mini chocolate chips and M&Ms

These cookies became a staple of mine when I was in college and grad school, and to this day, I’m remembered for their impossibly chewy and soft texture, and of course their unbeatable taste.

Unbaked cookies on baking sheet with cookie scoop

My husband jokes that these are a healthy dessert, courtesy of the lack of flour and addition of oats and peanut butter. While “health food” may be a stretch, you can guarantee they are a crowd-friendly dessert. (But if you are looking for a healthy sweet, don’t miss my famous 5-Minute Frozen Yogurt!)

Freshly baked monster cookies cooling on wire rack

The creepy candy eyes are an optional addition, but they’re a festive decorative touch in October when all things Halloween rule the food scene.

No stand mixer? No problem! I made these cookies dozens of times all through college sans mixer. (Consider the stirring your workout for the day.) And both smooth and chunky peanut butter will work, but I love the added crunch that chunky offers.

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Monster Cookies

Chocolatey, chewy, peanut buttery goodness. There's no better way to describe this tried and tested family recipe for Monster Cookies.
Author: Kelly Senyei
4.91 from 324 votes
Monster Cookies studded with mini chocolate chips and M&Ms
Prep Time 15 minutes
Cook Time 20 minutes
Total Time 35 minutes
Servings 24 cookies


  • 1 cup sugar
  • 1 cup packed light brown sugar
  • 1/2 cup unsalted butter, at room temperature
  • 3 large eggs
  • 1 1/2 cups peanut butter (smooth or chunky)
  • 1 Tablespoon vanilla extract
  • 2 teaspoons baking soda
  • 1/2 teaspoon salt
  • 4 1/2 cups oats (Old Fashioned or Quick)
  • 1 cup mini M&Ms
  • 1 cup mini-chocolate chips
  • Candy eyes (optional)


  • Pre-heat the oven to 350°F. Line two baking sheet with parchment paper or Silpat baking mats. 
  • In the bowl of a stand mixer fitted with the paddle attachment, cream together the sugar, brown sugar and butter until light and fluffy. 
  • Beat in the eggs, one at a time, and then beat in the peanut butter, vanilla, baking soda and salt until well combined.
  • Add the the oats and mix until combined, then add the mini M&Ms and mini-chocolate chips.
  • Scoop 2-to 3-tablespoon mounds of the dough onto the prepared baking sheets, spacing the mounds at least 2 inches apart. 
  • Bake the cookies for 12-15 minutes then remove them from the oven and allow them to cool for 5 minutes on the baking sheets before transferring them to a rack to cool completely. (See Kelly's Note.)

Kelly's Note:

  • The best way to guarantee your cookies are chewy and not too crispy is to underbake them slightly then remove them from the oven and allow them to cool for 5 to 10 minutes on the baking sheets.
  • If you're using the candy eyes, add them to the cookies immediately after you remove them from the oven.
  • ★ Did you make this recipe? Don't forget to give it a star rating below!


Calories: 343kcal, Carbohydrates: 41g, Protein: 7g, Fat: 17g, Saturated Fat: 6g, Cholesterol: 33mg, Sodium: 269mg, Potassium: 179mg, Fiber: 2g, Sugar: 29g, Vitamin A: 185IU, Vitamin C: 0.1mg, Calcium: 45mg, Iron: 1.3mg


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Recipe by Kelly Senyei of Just a Taste. Please do not reprint this recipe without my permission. If you'd like to feature this recipe on your site, please rewrite the method of preparation and link to this post as the original source.

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  1. Why does the butter and sugar take SO LONG to cream together? it’s been 30 minutes and still not light and fluffy!!

    1. Hi Kaitlyn – Did you start with room temp butter? You only need to beat the butter and sugar together for about 2 to 3 minutes at a moderate speed:)

  2. 5 stars
    Ooh, these are delicious!
    I added a little more salt (an additional 1/2 tsp) per another comment, since I like a good salty/sweet balanced cookie.
    Everyone lived them!

    I added a half a cup of mini marshmallows just for fun…..I will grease the cookie sheet better next time….super sticky, but delicious.

  3. I got this recipe from my mother 40 yrs ago and my family demands them as often as I can make them . I’m not a big peanut butter fan, but the combo of m&ms and chocolate chips makes them the best. Easy to make, a delight to eat.

  4. 5 stars
    These were fun to make. I do not own a stand-up mixer, so I had to use old fashioned arm strength. I substituted some of the chocolate chips with white chocolate chips instead for the heck of it.

    I eyeballed the three to four tablespoon size dough balls, and they still looked good! Who doesn’t love a little diversity in their cookie sizes. <3

    I cooked some at the recommend time of 12 to 15 minutes to see how those turn out consistency wise. They came out a lovely golden brown with crispy edges. The aromas were all peanut butter when the oven opened! I let them cool for five minutes before I had one myself and they are suuuuper rich. They have a nice crunch and a gooey interior! Absolutely delicious!

    I also cooked some the way Kelly suggested as well because my husband loves chewy, soft cookies. I only baked them for 11 minutes and 30 seconds. They turned out a soft sandy color, not golden like the 12–15-minute baked ones. These cookies are fall apart soft. I couldn't wait ten minutes to have one, but it is a must if you want them to keep their form!! These are melt-in-your-mouth gooey. So much softer than the others. My husband says they're amazing, but I prefer the 15-minute ones.

    So, all together, I give this a 5/5! Even better with a glass of cold milk! I'm going to be making these again guaranteed.

    1. Love, love, LOVE reading this, Madi! I’m thrilled you and your husband enjoyed the cookies!

  5. 5 stars
    These cookies turned out amazing!! So so delicious perfect timing finding your recipe too! Great addition for my kids teachers for teacher appreciation week. Definitely adding these to our cookie rotation.

  6. 5 stars
    WOAH these are amaaaazing!!!! Everyone loved them! This will be my go to recipe forever and ever. Thank you!!!!

  7. 4 stars
    These were good cookies however I thought they were a little too sweet and they needed some more salt. I like their chewy texture.

  8. 5 stars
    So yummy and gluten free that I can eat way too many. Definitely a great recipe for sharing lots of great cookies with my mail carrier, friends and neighbors. My daughter requests these regularly for her and her boyfriend. Thank you for sharing your recipe with us baking folks!

  9. 5 stars
    We love these cookies! I used PB fit powder for lower fat and calories. I increased the oats to thicken the cookies.

  10. 5 stars
    Made 24 “monster” sized cookies with ice cream scoop. Pressed top down to flatten a little. Could easily double amount with smaller scoop. Baked for 11-12 mins, let stand for 5+ mins then racked. The may seem “mushy” but oats will soak up and set up cookie. Move to rack to cool fully. Will stay soft and chewy days later. Great chocolate and PB flavor. Oats add a nice texture. Nice that they are flourless. Also freeze very well. Everyone enjoyed immensely with Ice Cream and asked for recipe. Highly recommend. BJS

  11. 5 stars
    Very good. Easy to make. I used an ice cream scoop to get the 3 Tbls of cookie dough before baking.

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