If you're looking for more of a classic holiday cookie, give these Peanut Butter Oatmeal Monster Cookies a try! Oats, peanut butter, and M&Ms come together for chocolatey and nutty treat that everyone will enjoy.
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yes, monster cookies are a popular Christmas recipe
I recently learned that monster cookies are most popular in the Midwest and that most of the United States may not know what they are! 😂 So, for all the non-Midwesterners out there, let me give you a rundown. When I was younger, I legitimately thought these cookies were made from monsters. But, obviously, they're not. Monster cookies are made with peanut butter, oats, and M&Ms—and they're oh so yummy!
From the name, you'd think they'd be a Halloween cookie. However, they're super popular to make around Christmas!
This Peanut Butter Oatmeal Monster Cookie recipe was developed and tested by my youngest sister, Lily, who is the all-star baking in my household. And let me tell you. She really hit it out of the park. I love the nutty oatmeal flavor in addition to the chocolately crunch from the M&Ms.
Feel free to add your own twist to these Oatmeal Monster Cookies when you're making them by adding what you like! Crushed up pretzels, marshmallows, candy bar pieces...there are so many options to choose from!
Ingredients for Oatmeal Monster Cookies
Butter: You'll want to let this soften at room temperature, therefore making itt easier to handle and it will produce the creamy texture we need for our batter.
Sugar: We'll be using both brown and white sugar in this cookie recipe.
Peanut Butter: What's a PB cookie without the PB? So yummy!
Eggs: These play an important role in providing structure and texture to our cookies!
Water: Introducing some moisture into the dough will make it easier to handle and scoop.
Vanilla Extract: To enhance all of the sweet flavors we've got going on!
Flour: I used all purpose flour. However, you can use a gluten free flour if needed! I haven't tried these cookies with any other flours.
Cornstarch: Helps create that great cookie texture.
Baking Soda: Without baking soda, our cookies would be pretty flat and non-monster like.
Salt: Also enhances the flavors in these cookies.
Oats: I used old fashioned oats.
M&Ms: Chocolate candy + cookies = YUM! Plus, they're certainly a monster cookie classic!
Kitchen equipment you'll need
To make these Peanut Butter Oatmeal Monster Cookies, you'll need a handheld mixer, mixing bowl, sheet pan, measuring cups and spoons, cookie scoop, parchment paper, and a rubber spatula.
How to make make Oatmeal Monster Cookies
- In a mixing bowl, cream together softened butter, peanut butter, brown sugar, and white sugar.
- Next, beat in eggs, vanilla, and water.
- Fold in flour, cornstarch, baking soda, and salt.
- Then, add in old fashioned oats and M&Ms. Combine.
- Refrigerate the cookie dough for 20 minutes.
- While cookie dough is chilling, preheat the oven to 350°F.
- After cookie dough has chilled, use a cookie scoop to place balls of dough onto your parchment paper lined baking sheet.
- Bake for 12-15 minutes or until the edges of the cookies are golden brown.
Oatmeal Monster Cookies FAQs
Why are these called monster cookies?
They're called monster cookies because of their mash up of different cookie ingredients. This is what makes them ‘monstrous’. Monster cookies are very popular in the Midwest, but a lot of other people around the US probably haven't heard of them! You may find this article sharing the most popular holiday cookies in each state as interesting as I did!
How do I store Oatmeal Monster Cookies?
I highly recommend storing in the fridge in an airtight container. I also recommend layering parchment paper between each cookie stack. This will prevent the cookies from molding together.
What's the best way to shape these cookies?
A cookie scoop is ideal for evenly shaped cookies. Thanks to the oats, these cookies don't markedly spread. I like to press them down a bit with the back of a spoon right when they come out of the oven to get perfectly round and even cookies.
Is parchment paper required?
When you’re baking in multiple batches, it’s hard to remove cookies quickly and reuse the pan. Parchment paper makes it easy to use the same pan between batches because you don't have to clean it. While it's not required, I highly recommend it.
Do I need to use peanut butter?
You can use any nut or seed butter. Cookie butter or granola butter would also be decadent. You can also try using crunchy peanut butter instead of smooth to add another texture element.
Can I make these monster cookies gluten-free/flourless?
The recipe only calls for ¼ a cup of flour. However, you can replace this with a 1:1 gluten-free baking flour or ¼ cup of pulsed oats (oat flour). I don’t suggest just using additional old fashioned oats because they will mess with the texture of your cookie.
Can I add any other mix-ins?
Like my No Bake Avalanche Cookies, I encourage you to use your favorite mix-ins in addition to the M&Ms or as a replacement. I suggest chopped Reese’s, chocolate chips, butterscotch chips, chopped pretzels, coconut flakes, or sprinkles. The possibilities are endless!
Other cookie recipes you might like
Shortbread Christmas Cookies with Icing
White Chocolate Dipped Peppermint Cookies
Chocolate Chip Pretzel Peanut Butter Cookies
Oatmeal Monster Cookies
Equipment
- Hand Mixer
- Mixing Bowl
- Baking sheet
- parchment paper
- Measuring cups and spoons
- Rubber Spatula
- Cookie scoop
Ingredients
- 1 stick butter
- 1 cup brown sugar
- ½ cup white sugar
- ⅔ cup peanut butter
- 3 eggs
- ⅛ cup water
- 1 tbsp vanilla extract
- ¼ cup all purpose flour
- ½ tsp cornstarch
- ¾ tsp baking soda
- ½ tsp salt
- 3¼ cup old fashioned oats
- 1 cup M&Ms
Instructions
- In a mixing bowl, cream together softened butter, peanut butter, brown sugar, and white sugar.
- Next, beat in eggs, vanilla and water.
- Fold in flour, cornstarch, baking soda, and salt.
- Then, add in old fashioned oats and M&Ms. Combine.
- Refrigerate the cookie dough for 20 minutes.
- While cookie dough is chilling, preheat the oven to 350°F.
- After cookie dough has chilled, use a cookie scoop to place balls of dough onto your parchment paper lined baking sheet.
- Bake for 12-15 minutes or until the edges of the cookies are golden brown.
Notes
I’d love to hear your thoughts in the comments below. It’s my passion to create dishes that can be shared with others. Tell me something you loved, something that you think it might need, or just say hi!
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Oh boy! I think I may be the cookie monster after making these monster cookies. They are SO GOOD. The texture is unbeatable and who doesn't love a peanut butter chocolate combo😍😍
So easy and yummy!!
Delish!! Easy to make… and made a lot! 🤩
These were delicious!! If you love peanut butter, make these!! I doubled the batch and it made a lot of cookies!!
one of my favorite recipes yet😍 so good!
This recipe leaves out when to add the vanilla in the directions
Hi there! Thanks for the catch on this:) It get's added with the wet ingredients (eggs and water). Recipe card has been updated to reflect this