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.
About these Cookies
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.
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!
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 or check out these No Bake Avalanche Cookies, Snickerdoodle Oatmeal Cookies, Peanut Butter Crinkle Cookies, Almond Butter Blossoms, Cherry Chip Cookies, or these White Chocolate Peppermint Cookies, too as other holiday favorites.
- Oats: I used old fashioned oats. Quick oats are too mushy for this recipe.
- 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!
- 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.
- M&Ms: Chocolate candy + cookies = YUM! Plus, they're certainly a monster cookie classic!
See the recipe card below for a full list of ingredients and measurements.
How to Make This Recipe
1. In a mixing bowl, cream together softened butter, peanut butter, brown sugar, and white sugar. Next, beat in eggs, vanilla, and water.
3. Fold in flour, cornstarch, baking soda, and salt.
4. 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.
5. After cookie dough has chilled, use a cookie scoop to place balls of dough onto your parchment paper lined baking sheet.
6. Bake for 12-15 minutes or until the edges of the cookies are golden brown. Remove from cookie sheet (onto wire cooling rack or sliding the parchment off the baking sheet), let cool, and enjoy!
Storing and Freezing
These can be stored in an airtight container either on the counter or in the refrigerator if you like a chewy, chilled cookie. In your storage container, add a piece of bread (I like to use the end piece of a loaf). The cookies will draw out the moisture from the bread and keep your cookies soft.
You can also freeze these cookies baked or unbaked:
- To freeze unbaked dough, scoop, roll in the sugar and place on a cookie sheet as if you’re going to bake them. Place the entire cookie sheet in the freezer for 3-4 hours until each dough ball is frozen (this’ll prevent them from sticking together). Then, place in a Ziplock or airtight container until ready to bake. You can bake the dough balls from frozen for 2-3 extra minutes.
- To freeze baked cookies, allow them to cool completely before adding to a freezer bag or airtight container. I recommend layering parchment paper between each cookie stack. This will prevent the cookies from freezing altogether.
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 most popular holiday cookies article in each state as interesting as I did!
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.
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.
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!
More Recipes You'll Love
Love this recipe? Please leave a 5-star 🌟🌟🌟🌟🌟rating in the recipe card below & if you really like the recipe consider leaving a comment further down. Thanks for visiting!
Oatmeal Monster Cookies
- Hand Mixer
- Mixing Bowl
- Baking sheet
- parchment paper
- Measuring cups and spoons
- Rubber Spatula
- Cookie scoop
- 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
- 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.
- Slide parchment paper off cookie sheet or transfer cookies to wire rack to cool. Then, enjoy!
Looking for this in MyFitnessPal?
If you're using MyFitnessPal, search 'A Paige Of Positivity' and find PEANUT BUTTER MONSTER COOKIES calories and nutrition facts. Disclaimer: for most accurate macronutrients and caloric breakdown, it is recommended that you input each ingredient into your MyFitnessPal food diary.
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 or just say hi!
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!!
Michelle Gimbutis says
Delish!! Easy to make… and made a lot! 🤩
Molly Wooten says
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!
J. Johnson says
This recipe leaves out when to add the vanilla in the directions
Sydney Van Acker says
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
Courtney Paige says
The best thing about these cookies is how easy they are to make! Great for a cookie exchange.