Home Desserts Easy Monster Cookies Recipe (Thick & Chewy)

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Easy Monster Cookies Recipe (Thick & Chewy)

Make the ultimate thick, chewy monster cookies recipe. Packed with peanuts, butter, oats, chocolate chips, and M&Ms.

  • Prep20 min
  • Cook15 min
  • Total55 min
  • Serves36 cookies

Published 16 Jun 2026

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A plate of cookies with colorful chocolate candies and chocolate chips sits on a checkered towel, with more cookies on a cooling rack and a glass of milk in the background.

If you need a quick win this week that makes the whole house smell like a bakery and keeps the kids completely happy, then you must make a batch of these thick,chewy monster cookies. Made with creamy peanut butter, chocolate chips, and M&Ms, these will make any day brighter.

I’ve made this recipe dozens of times for bake sales, after-school snacks, and late-night cravings. What I love the most is that it’s very forgiving and easy to customize. There are no fancy ingredients or equipment needed just some basic pantry staples and colorful candy that’s hiding out in your cupboard. These monster cookies are soft in the center and perfectly crisp on the edges.

A plate of cookies with colorful chocolate candies and chocolate chips sits on a checkered towel, with more cookies on a cooling rack and a glass of milk in the background.

What is a Monster Cookie?

Amonster cookieis a thick, ultra-chewy cookie that combines the rich flavor of peanut butter with the hearty texture of an oatmeal cookie. They are highly popular because of their customizable ingredients, quick baking time, and easy to use for meal prep.

Key Takeaways

  • Ready in under an hourwith just about 20 minutes of prep time and a little bit of chill time!
  • Easy pantry ingredientslike brown sugar, oats, and peanut butter.
  • Can easily bemade gluten-freewith certified gluten-free oats and gluten-free all-purpose flour.
  • Make a large batchand use it throughout the week for lunches and meal prep.
  • Thesugar and oats combinationguarantees a thick cookie that stays soft for days.
  • The dough can also bemade and frozenuntil ready to use!

Ingredient Notes

A baking tray lined with parchment paper holds twelve freshly baked cookies with chocolate chips and colorful candy-coated chocolates. The cookies are arranged neatly in rows.

Butter:Use softened, unsalted or salted butter to add the rich flavor.

Creamy Peanut Butter:Use a classic creamy peanut butter like Jif or Skippy; do not use natural peanut butter as it will make the dough too oily.

Granulated Sugar:This sugar gives the cookies the crisp edges.

Brown Sugar:The brown sugar adds moisture for the rich molasses undertones and soft centers.

Eggs:Use eggs to bind the dough together and add richness.

Vanilla Extract:Vanilla rounds out the sweet flavors.

All-Purpose Flour:Adds structure to the cookie dough.

Old Fashioned Oats:Provide that signature chewy texture.

Baking Soda:Baking soda helps the cookies rise and spread just enough.

Salt:Balances out the sweetness of the chocolate.

Chocolate Chips:Adds the sweetness to the cookies.

M&Ms:Gives additional sweetness and a pop of color.

How to Make Monster Cookies

A cooling rack filled with freshly baked cookies containing chocolate chips and colorful candy-coated chocolates, with a checkered cloth underneath.
  1. In a large mixing bowl, beat the butter and peanut butter together until smooth and creamy.
  2. Add the granulated sugar and brown sugar and beat until light and fluffy.
  3. Add the eggs and vanilla extract and mix until combined.
  4. Add the flour, oats, baking soda, and salt and stir until just incorporated.
  5. Fold in the chocolate chips and M&M candies.
  6. Cover the dough and chill for at least 20 minutes or up to overnight.
  7. Preheat the oven to 350°F and line baking sheets with parchment paper or silicone baking mats.
  8. Scoop the dough into 2-tablespoon-sized balls and place them about 2 inches apart on the prepared baking sheets.
  9. If desired, press a few extra chocolate chips or candies onto the tops of the dough balls to make the cookies extra pretty.
  10. Bake for 12–15 minutes, until the edges are lightly golden and the centers are set.
  11. Let the cookies rest on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.

Pro Tips for the Best Monster Cookies

A plate of homemade cookies with colorful candy-coated chocolates and chocolate chips sits on a striped cloth, with more cookies and a glass of milk in the background.
  • Usethicker peanut butterlike Jif or Skippy. Natural peanut butter will be too oily and affect the texture of the cookies.
  • Chilling the doughhelps the cookies remain thick and chewy during baking.
  • Do not overbakethe cookies; they will continue to bake and set as they cool.
  • Old-fashioned oatsgive the cookies the best chewy texture.
  • The cookie dough can bestored frozen in the freezerand then baked straight from the freezer by adding an extra 1-2 minutes.

Variations and Substitutions

A cooling rack holds oatmeal cookies with colorful candy-coated chocolates and chocolate chips. More cookies are stacked on a plate nearby, with a glass of milk in the corner.
  • Swap the candies for different colors and variations, such as red and green for the Christmas holiday or orange and black for Halloween.
  • If you have a peanut allergy, use sunflower seed butter or SunButter, it’s a 1:1 substitute.
  • Add 1/2 cup crushed pretzels for loaded monster cookies.
  • Make it gluten-free by using gluten-free all-purpose flour and certified gluten-free old-fashioned oats.

Frequently Asked Questions

Can I make monster cookie dough ahead of time?

Mix the dough, cover it tightly, and keep it in the fridge for up to 3 days before baking. The dough can also be stored in the freezer until ready to bake.

Why did my monster cookies turn out flat?

Flat cookies usually happen if the cookie dough wasn’t chilled long enough or if the butter was completely melted instead of softened.

Can I use quick oats instead of old-fashioned oats?

Quick oats will work in a pinch as a 1:1 swap; however, they do absorb moisture faster and make the cookies denser and less chewy.

How do I keep the cookie soft?

Store the cookies in an airtight container at room temperature with a single slice of white bread. The cookies will absorb moisture from the bread and stay soft for up to 5 days.

What to Serve with Monster Cookies

A close-up of a cookie with colorful chocolate candies and a bite taken out, resting on the rim of a glass of milk. More cookies are visible on a plate and a wire rack in the background.

Storage and Reheating

Room Temperature

Store the baked cookies in an airtight container at room temperature for up to 5 days. Place a slice of bread inside the container to help the cookies stay soft. These cookies do not need to be refrigerated.

Freezer

Store the baked cookies or raw dough balls in a heavy-duty freezer bag for up to 3 months. It’s best to flash freeze the cookies on a cookie sheet in the freezer for 1-2 hours before placing them in the freezer-safe bag.

Reheating

For the straight out of the oven taste and texture, heat the baked cookies in the microwave on a microwave-safe plate for 8 to 10 seconds. If baking frozen dough balls, bake them straight from the freezer, adding 1 to 2 minutes to the baking time.

More Cookie Recipes

These easyMonster Cookiesare proof that simple, everyday pantry items can turn into a memorable treat that brings everyone around the kitchen table to share about their day. Mix it up with a variety of add-ins or different colors to make festive monster cookies!