These Monster Cookies are loaded with M&Ms, chocolate chips, and raisins – they’re thick, chewy, and oh-so-good! This flourless cookies recipe is just the thing for those who love the chocolate-peanut butter combo!

A stack of monster cookies

Thick & Chewy Monster Cookies

Chocolate + peanut butter is the hands-down winning dessert combination of flavors in our house. And these Monsters Cookies are a top favorite family recipe!

My sister, Jessica, passed this recipe on to me many years ago, and it remains a favorite to this day. These cookies are thick and chewy, and loaded with peanut butter and chocolate – absolutely irresistible!

I love that my sister makes these cookies the size of normal homemade cookies, and not the typical monster cookies the size of salad plates. Because I can simply never finish one of those giant cookies! So I affectionately call these: Jessica’s “Not-So-Monster” Monster Cookies. And I think they’re PERFECT!!

A hand holding a monster cookie with a bite missing

What Are Monster Cookies?

Monster cookies are flourless cookies made with oats and peanut butter, then loaded with mix-ins like chocolate chips, M&Ms, and raisins. They’re thick, chewy, and usually quite big – though this recipe features more normal-sized cookies than you’ll find elsewhere.

Overhead view of monster cookie ingredients

What You’ll Need

These flourless peanut butter cookies are made with a handful of pantry staples plus mix-ins like M&Ms and chocolate chips.

  • Eggs
  • Sugar – This recipe calls for both brown sugar and granulated sugar. Brown sugar gives a deeper, warmer sweetness, while also adding moist texture.
  • Unsalted butter
  • Vanilla extract
  • Light corn syrup
  • Baking soda – Helps the cookies rise a bit and creates the chewy texture.
  • Peanut butter – My family prefers creamy peanut butter, though crunchy peanut butter would also be good. All natural peanut butters are not ideal for this recipe. We use Skippy!
  • Oats – Old fashioned oats are best, though quick oats will also work. Avoid steel cut oats.
  • Mix-ins – We use semi-sweet chocolate chips, M&Ms, and raisins (and sometimes our kids request to leave out the raisins, no problem!). You could also add dark chocolate chips, peanut butter chips, crushed candy pieces, etc.

How to Make Monster Cookies

These thick and chewy monster cookies are super easy to make, with no chill time required.

  • Make the dough. Beat the eggs, then add the sugars and butter. Beat until incorporated. Add the vanilla, corn syrup, baking soda, peanut butter, and oats.
  • Add the mix-ins. Once the oats are evenly incorporated, stir in the mix-ins with a wooden spoon.
  • Bake. Scoop dough into 2-tablespoon balls and place on a baking sheet. Press additional mix-ins into the dough if desired. Bake for 12 minutes, or until edges are lightly browned. Let cool on the baking sheet for 5 minutes, then transfer to a cooling rack.
A hand grabbing a monster cooking from a cooling rack

Tips for Success

Here are a few tips for the best flourless cookies.

  • Avoid steelcut oats. I prefer old fashioned oats but quick oats will work as well, though you won’t have the same whole oat texture. Steel cut oats, on the other hand, will not soften and will not give your cookies a pleasing texture.
  • Use 1 cup of mix-ins. Vary the mix-ins however you like, adding more of your favorite or omitting one, but aim for 1 cup total.
  • Scoop the dough tightly. Tightly back the dough into the cookie scoop, to be rewarded with thick, chewy cookies that don’t spread too much in the oven.
  • Use room temperature butter. The butter should be room temperature but not melted. This is important since the dough isn’t chilled. Melted butter will cause the cookies to spread too much during baking.
  • Make large cookies. If you want the traditional “monster sized” monster cookies, roll the dough into bigger balls and adjust the cooking time for a longer bake time.
A hand dipping a monster cookie into a glass of milk

How to Store & Freeze

Monster cookies will keep well at room temperature for up to 5 days. Just keep them stored in an airtight container or ziploc bag.

These flourless peanut butter cookies also freeze extremely well. Allow them to cool completely, then freeze in a freezer-safe ziploc bag or container for up to 3 months. You can thaw them in the fridge or on the counter – or pop them into the microwave for a few seconds to enjoy warm!

More Cookie Recipes:

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A stack of monster cookies

Jessica’s “Not-So-Monster” Monster Cookies

Yield: 60 cookies
Prep Time: 10 minutes
Cook Time: 1 hour
Total Time: 1 hour 10 minutes

These Monster Cookies are loaded with M&Ms, chocolate chips, and raisins - they're thick, chewy, and oh-so-good! This flourless cookies recipe is just the thing for those who love the chocolate-peanut butter combo!

Ingredients

  • 4 large eggs
  • 1½ cups packed brown sugar
  • 1⅓ cups granulated sugar
  • 1⅓ sticks good quality unsalted butter, at cool, softened room temperature
  • 2 teaspoons pure vanilla extract
  • 1 teaspoon light corn syrup
  • 2½ teaspoons baking soda
  • 1⅔ cups creamy peanut butter - I use Skippy
  • 6 cups old fashioned oats
  • 1/3 cup semi-sweet chocolate chips - I use Guittard brand
  • 1/3 cup regular M&M candies
  • 1/3 cup raisins

Instructions

  1. Preheat oven to 350° F.
  2. In a large mixing bowl, beat eggs briefly. Then add brown sugar, granulated sugar, and butter, and beat on medium speed until incorporated.
  3. Add vanilla, corn syrup, baking soda, peanut butter, and oats, and mix on medium-low speed until oats are very evenly incorporated. Then fold in chocolate chips, M&M candies, and raisins with a sturdy spatula or wooden spoon. (You can vary the mix-ins however you like, just aim for 1 cup total.)
  4. Scoop dough tightly with a 2-tablespoon scoop and place dough on a sturdy, non-coated baking sheet. Press in additional mix-ins if desired.
  5. Bake for about 12 minutes, or until edges are lightly browned. Remove baking sheet from oven and let cookies cool on pan for 5 minutes, and then transfer cookies to a cooling rack.

Notes

Adapted by my sister Jessica from the 75th Jubilee (1988) Claire City-New Effington, SD Cookbook, original recipe by Kristi Bostrom.

Nutrition Information:
Yield: 60 Serving Size: 1
Amount Per Serving: Calories: 147Total Fat: 7gSaturated Fat: 3gTrans Fat: 0gUnsaturated Fat: 4gCholesterol: 18mgSodium: 97mgCarbohydrates: 19gFiber: 1gSugar: 11gProtein: 3g

Nutrition information is automatically calculated by Nutritionix. I am not a nutritionist and cannot guarantee accuracy. If your health depends on nutrition information, please calculate again with your own favorite calculator.

Did you make this recipe?

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A stack of monster cookies

This post was originally published in 2010, then updated with new photos and text in 2022.