If you’ve ever wanted a cookie that brings together the best of peanut butter, oats, chocolate, and colorful candy, then this Monster Cookies Recipe is exactly what you need in your life. These cookies are chewy, packed with texture, and bursting with flavors that feel like a warm hug from your childhood. Whether you’re baking for a party or just treating yourself after a long day, these Monster Cookies deliver that perfect balance of sweetness and hearty goodness that will have everyone asking for seconds.

Ingredients You’ll Need
The magic of this Monster Cookies Recipe lies in its simple yet mighty ingredients that come together to create layers of texture and flavor. Each component plays a crucial role, from the creamy peanut butter adding richness, to the oats bringing a wholesome chewiness, and the M&M’s delivering a joyful pop of color and sweetness.
- 1 cup creamy peanut butter: Provides the base flavor and a creamy texture that binds the cookies.
- 1/2 cup unsalted butter (softened): Adds richness and helps create a tender crumb.
- 1 cup brown sugar (packed): Imparts moisture and a deep caramel sweetness.
- 1/2 cup granulated sugar: Balances sweetness with a slight crispness on the edges.
- 2 large eggs: Acts as a binder and adds moisture for soft cookies.
- 1 teaspoon vanilla extract: Enhances the overall flavor with a warm, aromatic note.
- 1 1/2 teaspoons baking soda: Helps the cookies rise just enough while keeping them chewy.
- 1/2 teaspoon salt: Balances sweetness and intensifies flavors.
- 2 cups old-fashioned oats: Adds wholesome texture and chewiness.
- 1 cup all-purpose flour: Provides structure for the cookies to hold their shape.
- 3/4 cup chocolate chips: Melts through the cookies for gooey pockets of chocolate.
- 3/4 cup M&M’s: Brings vibrant colors and crunch, making each bite fun.
- 1/2 cup mini chocolate chips (optional): Adds extra chocolatey goodness without overpowering the mix.
How to Make Monster Cookies Recipe
Step 1: Prep and Mix the Wet Ingredients
Begin by preheating your oven to 350°F (175°C) and lining your baking sheets with parchment paper to ensure easy removal later. In a large bowl, beat together the creamy peanut butter, softened butter, brown sugar, and granulated sugar until the mixture turns smooth and creamy. This step is essential as it builds the rich, buttery base that will make your cookies delightfully tender.
Step 2: Add Eggs and Flavors
Next, mix in the eggs one at a time along with the vanilla extract. These ingredients will bring moisture and flavor depth, setting up the perfect foundation for the cookies to come alive. Don’t rush — make sure everything is well incorporated for the best results.
Step 3: Incorporate Dry Ingredients
Sprinkle in the baking soda and salt, stirring to combine. Then gradually add the old-fashioned oats and all-purpose flour, mixing gently until everything is just combined. The oats give these cookies their signature chewy texture while the flour ensures they hold their classic shape.
Step 4: Fold in the Chocolate and Candy
The moment we’ve all been waiting for — folding in the chocolate chips, M&M’s, and if you’re using them, the mini chocolate chips. This colorful mix not only brings bursts of sweetness but also makes every bite a delightful surprise of crunchy candy and melted chocolate.
Step 5: Bake to Perfection
Scoop out the dough using about 2-tablespoon portions onto your prepared baking sheets, spacing them roughly 2 inches apart to allow for slight spreading. Bake for 10 to 12 minutes, just until the edges are lightly golden and the centers look set but still soft. Remember, slightly underbaking means chewier cookies, so keep a close eye on them!
Step 6: Cool and Enjoy
Let your cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack. This resting time lets the cookies finish setting while keeping them perfectly soft in the middle and satisfyingly chewy around the edges.
How to Serve Monster Cookies Recipe

Garnishes
Although these cookies are delicious on their own, you can dress them up with a light sprinkle of sea salt just before serving to make the chocolate and peanut butter flavors shine even more. A dusting of powdered sugar also adds a festive touch without masking the cookie’s rich flavors.
Side Dishes
Pair your Monster Cookies with a tall glass of cold milk or a creamy cup of coffee for a classic combo. If you want to get fancy, serve alongside vanilla ice cream or a scoop of rich chocolate gelato for an indulgent dessert experience.
Creative Ways to Present
If you’re bringing these cookies to a party, try stacking them with layers of frosting in between to create mini cookie sandwiches. You can also dip one edge into melted chocolate or nut butter and let them set for an extra special treat that’s almost too beautiful to eat.
Make Ahead and Storage
Storing Leftovers
You can keep your Monster Cookies fresh by storing them in an airtight container at room temperature for up to five days. To maintain their soft and chewy texture, place a slice of bread inside the container — it keeps moisture balanced and prevents them from drying out.
Freezing
If you want to enjoy these cookies later, freezing is a great option. Place the cooled cookies in a single layer on a baking sheet to flash freeze, then transfer them to a freezer-safe bag or container. They will keep well for up to three months, allowing you to thaw and enjoy a sweet treat whenever the craving hits.
Reheating
To bring your Monster Cookies back to life after freezing or storage, pop one or two in the microwave for about 10 seconds or warm them in a low oven for a few minutes. This quick step revives their soft, melty texture just like fresh from the oven.
FAQs
Can I substitute the peanut butter with another nut butter?
Absolutely! Almond butter or cashew butter can work nicely, but keep in mind the flavor and texture will vary slightly. Peanut butter’s unique creaminess and taste are what give these cookies their signature monster appeal.
Are Monster Cookies gluten-free?
As written, the recipe includes all-purpose flour which contains gluten. However, you can experiment with gluten-free flour blends to make a gluten-free version. Just be sure to test the dough’s consistency as adjustments might be needed.
Can I make these cookies vegan?
To make this Monster Cookies Recipe vegan, swap the butter with coconut oil or vegan margarine, and replace eggs with flax eggs or another vegan egg substitute. Keep in mind you’ll also want to use dairy-free chocolate chips and M&M’s that are vegan-friendly.
Why do the cookies come out flat sometimes?
Flat cookies often result from over-softened butter or not enough flour. Be sure your butter is softened but not melted, and measure your flour accurately. Chilling the dough for a bit before baking can also help maintain their shape.
Can I add nuts or other mix-ins?
Definitely! Chopped walnuts, pecans, or butterscotch chips make fantastic additions. Just fold them in with the chocolate chips and M&M’s to personalize your Monster Cookies Recipe to your taste preferences.
Final Thoughts
There is nothing quite like biting into a fresh Monster Cookie that’s loaded with peanut butter, oats, chocolate, and colorful candy. This recipe is a true winner when you want a treat that’s hearty, nostalgic, and irresistibly tasty. Give this Monster Cookies Recipe a try—you might just find your new favorite cookie that everyone will love as much as you do!
Print
Monster Cookies Recipe
- Prep Time: 15 minutes
- Cook Time: 12 minutes
- Total Time: 27 minutes
- Yield: 24 cookies
- Category: Dessert
- Method: Baking
- Cuisine: American
- Diet: Vegetarian
Description
These Monster Cookies are a deliciously chewy and colorful treat packed with peanut butter, oats, chocolate chips, and M&M’s. Perfectly soft with a hint of crisp edges, these classic American dessert cookies bring together a delightful mix of textures and flavors for an irresistible snack or dessert.
Ingredients
Wet Ingredients
- 1 cup creamy peanut butter
- 1/2 cup unsalted butter, softened
- 2 large eggs
- 1 teaspoon vanilla extract
Dry Ingredients
- 1 cup brown sugar, packed
- 1/2 cup granulated sugar
- 1 1/2 teaspoons baking soda
- 1/2 teaspoon salt
- 2 cups old-fashioned oats
- 1 cup all-purpose flour
Add-Ins
- 3/4 cup chocolate chips
- 3/4 cup M&M’s
- 1/2 cup mini chocolate chips (optional)
Instructions
- Preheat and Prepare Pans: Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper to prevent sticking and ensure even baking.
- Cream Butter and Sugars: In a large bowl, beat together the creamy peanut butter, softened unsalted butter, brown sugar, and granulated sugar until the mixture is smooth and creamy, creating the base of the cookie dough.
- Add Eggs and Vanilla: Add the eggs and vanilla extract to the mixture and mix well until fully combined, adding moisture and flavor to the dough.
- Mix Dry Ingredients: Stir in baking soda and salt to evenly distribute the leavening agent and seasoning.
- Combine Oats and Flour: Gradually add the old-fashioned oats and all-purpose flour, mixing until just incorporated to form the cookie dough.
- Fold in Add-Ins: Gently fold in chocolate chips, M&M’s, and mini chocolate chips if using, to distribute these treats evenly throughout the dough.
- Scoop Dough: Using a spoon or cookie scoop, portion the dough into 2-tablespoon sized scoops and place them on prepared baking sheets spaced about 2 inches apart to allow for spreading.
- Bake: Bake for 10 to 12 minutes until the edges turn lightly golden and the centers are just set, ensuring soft and chewy cookies.
- Cool: Let the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely, helping them firm up while retaining a chewy center.
Notes
- You can customize these cookies by adding chopped nuts, butterscotch chips, or peanut butter chips for extra flavor and texture.
- For softer cookies, slightly underbake them and store in an airtight container to maintain moisture.

