These extra-large, chewy monster cookies are the ULTIMATE cookie! They’re packed with chocolate chips, M&Ms, peanuts, rolled oats, and crispy rice cereal.

These extra-large monster cookies are the ultimate cookie! They're packed with M&Ms, oats, chocolate chips, peanuts, and crispy rice cereal. 

Not surprisingly, chocolate chip cookies are a regular at our house. But sometimes I want more than just plain chocolate chip. Sometimes, I just want to open up my pantry and dump all the yummy things I find into the mixer— nuts, candy, chocolate, the works.

Does this ever happen to you? These monster cookies are the answer! And while you can add almost anything you want to these monster cookies (I’ve got plenty of variations below!), I’m a pretty big fan of this combo. They’re thick and chewy, and have a fun flavor and great texture.

Table of Contents

ingredients for monster cookies

What are monster cookies?

Monster cookies are the “monster” of the cookie world, and a combination of a lot of different cookie recipes. Like a peanut butter cookie, an oatmeal cookie, and a chocolate chip or M&M cookie all in one!

You’ll find recipes with varying mix-ins, but here’s what you’ll find in my monster cookie recipe:

  • Semisweet chocolate chips
  • Mini M&Ms
  • Chopped peanuts
  • Old-fashioned oats
  • Crispy rice cereal

It’s the perfect combo of chocolate, candy, and nuts, and lots of chewiness from the oats and crispy rice cereal (seriously, my favorite mix-in here!). Many other monster cookies also include peanut butter, while mine does not. A lot of monster cookies also have no flour, but mine do! There’s no one right way to make ’em! 😊

Mixing and making monster cookies

How to make monster cookies

  1. Gather ingredients and mix-ins. Decide what you’ll use, whether you follow this recipe as written, or get creative. You’ll need 1 1/2 – 2 cups max.
  2. Prepare monster cookie dough. This is a standard drop cookie recipe. So first you beat the butters and sugars till creamy, then add eggs and vanilla, followed by the dry ingredients and the mix-ins. 
  3. Portion into cookie dough balls. Since these cookies are so loaded up, you really need to make larger cookies for them to be shaped right. Use a large #20 (3 Tbsp) cookie scoop.
  4. Add more mix-ins on top. This is important! Without this step you really don’t get the full effect of what’s inside.
  5. Bake. They’ll need about 11-12 minutes in a 375°F oven. Let them finish setting up on the pan for at least 5 minutes.
  6. Enjoy! These cookies are delicious within 1-2 days of baking, after that they start to dry out.
These extra-large monster cookies are the ultimate cookie! They're packed with M&Ms, oats, chocolate chips, peanuts, and crispy rice cereal. 

Variations and substitutions

These really are the essential “clean out the pantry” cookies and you are free to change up the mix-ins to match your craving or what you have on hand already. Here are some ideas:

  • Use other baking chips: peanut butter chips, butterscotch chips, white chocolate chips, or a combination.
  • Use other candy: use regular M&Ms, Reese’s Pieces, mini peanut butter cups, chopped candy bars or other chocolate candies
  • Use other nuts: pecans, walnuts or almonds. (You can also leave out the nuts and replace with something else!)
  • Add coconut: reduce amount of crispy rice cereal to 1 1/2 cup and add 1/2 cup shredded coconut.
  • Start with butter at the right temperature. It should be softened to room temperature, but isn’t so warm that it’s at all melted. Your finger should just make a slight indent when pressed, not press all the way through. See my 4 ways to bring butter to room temperature.
  • How do you measure flour? All of my recipes are measured with the “spoon and sweep” method to ensure you don’t add too much (which results in dry cookies that don’t spread well).
  • Use pre-cut parchment sheets, they’re perfect for cookie baking. No-mess clean up!
  • Re-shape cookies while hot, if needed. If the cookies bake up in an irregular shape, use a flat edge to push the cookie back into a round shape. Do this immediately after removing them from the oven while they’re still soft and malleable.
  • Cookie dough freezes great! And it’s my secret for tasty and fresh cookies anytime the craving hits.

baking tip:How to keep cookies from spreading

Isn’t it the biggest bummer when you pop a tray full of cookie dough into the oven, only to pull out flat, greasy cookies? It happens to me too. It could be caused by a variety of reasons:

  • The temperature of the butter. I believe this is the #1 culprit when cookies spread! If the recipe calls for room temperature butter, make sure it isn’t too soft when you start making your dough. When you press a finger into the butter, it should just barely leave a dent.
  • Over-creaming the butter and sugar. Overbeating causes the butter to break down and release air bubbles, which can lead to flat and dense cookies.
  • A greased cookie sheet. Use parchment instead to prevent sticking without adding extra grease.

So what if you’re in the middle of baking a batch of cookies, they’re spreading in the oven, and you want to fix it? Try chilling the dough on the cookie sheet for 10-15 minutes before baking. This will hopefully slow down the process of spreading.

More Baking Tips »
These extra-large monster cookies are the ultimate cookie! They're packed with M&Ms, oats, chocolate chips, peanuts, and crispy rice cereal. 

Get the recipe

Monster cookies with a glass of milk
5 from 4 reviews

Monster Cookies

Servings: 24 cookies
Prep Time: 15 minutes
Cook Time: 12 minutes
Total Time: 27 minutes
These are the cookies to bake when you aren’t sure what you’re craving. They’re packed with M&Ms, oats, butterscotch chips, pecans, and crispy rice cereal.
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Ingredients
 

  • ¾ cup (85 grams) unsalted butter , at room temperature
  • 1 cup (215 grams) packed light or dark brown sugar
  • ½ cup (100 grams) granulated sugar
  • 2 large eggs
  • 1 tablespoon vanilla extract
  • 2 cups (240 grams) all-purpose flour
  • ½ teaspoons salt
  • 1 teaspoon baking powder
  • ½ teaspoon baking soda
  • 1 ½ cups (150 grams) rolled oats
  • ½ cup (108 grams) mini M&Ms
  • ¾ cup (128 grams) semisweet chocolate chips
  • ½ cup (70 grams) peanuts , chopped
  • 2 cups (70 grams) crispy rice cereal

Equipment

medium cookie scoop
Large cookie scoop
Sheet pans
Baking sheet pan
a box of pre cut parchment paper baking sheets
Parchment baking sheets

Instructions
 

  • Preheat oven to 375°F. Line a sheet pan with parchment paper or a silicone baking mat.
  • In the bowl of a stand mixer fitted with a paddle attachment, beat together the butter and sugars until light and creamy, about 1-2 minutes. Add the eggs one at a time, followed by the vanilla and mix until combined.
  • Add the flour, salt, baking powder, and baking soda and mix on low until just combined. Add the oats, chips, and nuts, M&Ms, and crispy rice cereal and mix until just combined.
  • Drop large rounds (I use a #20 – 3 tablespoon cookie scoop) onto the prepared sheet pan, 6-8 per pan. Bake until edges are golden brown and centers are just barely set, about 12 minutes.
  • Let cool on the sheet for 5 minutes, then transfer to a wire rack to cool completely. Store in an airtight container for several days.

Video

Calories: 244kcal, Carbohydrates: 33g, Protein: 4g, Fat: 11g, Saturated Fat: 6g, Cholesterol: 30mg, Sodium: 85mg, Potassium: 122mg, Fiber: 2g, Sugar: 18g, Vitamin A: 210IU, Calcium: 35mg, Iron: 1mg
Cuisine: American
Course: Dessert
Author: Annalise Sandberg
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Have you tried this recipe?I’d love to hear about it! Leave a rating and review below, or take a photo and tag it on Instagram @completelydelicious with #completelydelicious.

This recipe was originally published in 2013. Minor improvements to the recipe have been made, as well as clearer instructions and photographs.