If you have a sweet tooth and love a cookie that delivers big on flavor and fun, you are going to adore this Monster Cookies Recipe. These cookies are everything you want in a treat—chewy and soft with a bit of crunch, loaded with peanut butter, oats, and bursts of colorful M&Ms that make every bite exciting. Whether you’re baking for a crowd or just indulging yourself, these monster-sized delights are sure to impress and become an instant favorite in your baking repertoire.

Ingredients You’ll Need
Gathering the right ingredients is the first step to baking perfect Monster Cookies. Each one plays a vital role: the peanut butter brings rich creaminess, oats add texture and heartiness, while the M&Ms give that joyful pop of color and chocolatey sweetness.
- 1 cup salted butter (softened, 2 sticks): Creamy, softened butter ensures your cookies stay tender and help bind everything together.
- 1 cup dark or light brown sugar: Adds deep caramel notes and moisture for that chewy texture.
- 3/4 cup white sugar: Balances sweetness and contributes to the crispy edges.
- 1 cup peanut butter (creamy or chunky): The cookie star that gives the cookies their signature nutty flavor and richness.
- 2 eggs: Bind everything while making the cookies soft and cakey.
- 1 teaspoon vanilla: Enhances all the flavors and adds warmth.
- 1 & 1/2 cups flour (spooned and leveled): The base that gives structure to the cookies.
- 2 teaspoons baking soda: Helps the cookies spread and rise just right.
- 1 teaspoon salt: Balances sweetness and intensifies flavor.
- 1 cup quick oats: Adds chewiness and wholesome texture.
- 1/2 cup old fashioned oats: For a heartier bite and rustic appeal.
- 2 cups M&Ms (plus more for topping*): These colorful candies melt into pockets of chocolate, making the cookies a delight to look at and eat.
- Candy eyes (optional): A fun, whimsical touch to make your monster cookies truly come alive!
How to Make Monster Cookies Recipe
Step 1: Cream the Butter
Start by beating the softened butter in a large bowl or stand mixer for about 2 minutes, making sure to scrape the sides and bottom. This step is crucial for creating a light, fluffy base that will give your cookies the perfect texture.
Step 2: Mix in Sugars and Peanut Butter
Next, add both the brown sugar and white sugar along with the peanut butter. Beat these together until fully combined, producing a creamy mixture that smells heavenly and sets the stage for the rich peanut flavor that defines this Monster Cookies Recipe.
Step 3: Add Eggs and Vanilla
Now, crack in the two eggs and pour in the vanilla extract. Beat everything together thoroughly, making sure to scrape down the sides again so all ingredients come together in a smooth batter.
Step 4: Incorporate the Dry Ingredients
Add the flour to the bowl, but don’t mix yet. Use a small spoon to stir the baking soda and salt directly into the flour, then gently beat that mixture into your wet ingredients. Leave a few streaks of flour for a rustic cookie texture.
Step 5: Fold in Oats and M&Ms
Time to add the star textures! Stir in both the quick oats and old fashioned oats along with the two cups of M&Ms. Mix just enough to combine without overworking the dough—this keeps your cookies tender with those delightful chunks of candy.
Step 6: Chill the Dough
Cover your bowl with plastic wrap and refrigerate the dough for at least 1 hour, but 3 hours or even overnight is even better. Chilling solidifies the fats and enhances flavor, plus it helps the cookies hold their shape while baking.
Step 7: Prepare to Bake
Once chilled, preheat your oven to 350 degrees Fahrenheit. Line two baking sheets with silicone baking mats or parchment paper to keep your cookies from sticking and ensure even baking.
Step 8: Shape the Cookies
Using a large cookie scoop, shape the dough into balls about 2 inches across. Space them at least 2 inches apart on your baking sheets to give each cookie room to spread beautifully.
Step 9: Bake
Bake your cookies for 10 to 12 minutes, watching closely—the centers should look almost done with a shiny finish, and the edges should set firmly. Avoid overbaking to keep them soft and chewy inside.
Step 10: Add Extra M&Ms and Candy Eyes
Right after pulling the cookies from the oven, press additional M&Ms and candy eyes (if using) onto the tops while they’re still warm. For those who love tall, chewy cookies, push the edges inward slightly with a spoon to create a thick, satisfyingly chewy bite.
Step 11: Cool and Enjoy
Let the cookies cool on the sheet for 5 minutes before transferring to a cooling rack. The real fun begins as you eat these warm, melty beauties—one is never enough!
Step 12: Store Properly
Keep your Monster Cookies fresh by storing them covered on the counter. They’ll stay soft and delicious for days, although you’ll find they rarely last that long!
How to Serve Monster Cookies Recipe

Garnishes
To make your cookies even more eye-catching, add extra M&Ms or candy eyes on top right after baking. Sprinkle a pinch of flaky sea salt for a sweet-salty balance, or drizzle some melted chocolate for an extra indulgent touch.
Side Dishes
Monster cookies are fantastic on their own, but they also pair wonderfully with a cold glass of milk, a hot cup of coffee, or even vanilla ice cream for a decadent dessert. For brunch, serve alongside fruit salad to balance the richness.
Creative Ways to Present
Turn these cookies into party stars by arranging them on a platter with colorful napkins or placing them into decorative treat bags for sharing. You can also stack them to create a playful cookie tower, or sandwich a scoop of ice cream between two cookies for a monster-sized treat.
Make Ahead and Storage
Storing Leftovers
Store leftover monster cookies in an airtight container at room temperature. They’ll maintain their chewiness and freshness for up to a week—perfect for snacking anytime you crave a sweet pick-me-up.
Freezing
If you want to save some for later, freeze the cookie dough balls on a baking sheet first, then transfer them to a freezer bag. You can also freeze fully baked cookies in an airtight container. Both will keep well for up to 3 months.
Reheating
To enjoy your cookies warm again, microwave them for about 10 seconds or pop them in a 300-degree oven for 5 minutes. This revives their softness and melts the chocolate just right.
FAQs
Can I use crunchy peanut butter instead of creamy?
Absolutely! Crunchy peanut butter adds a delightful extra texture that complements the oats perfectly. Either creamy or chunky works well in this Monster Cookies Recipe.
Why do I need to chill the dough?
Chilling the dough solidifies the fats and lets the flavors meld together, resulting in cookies that keep their shape during baking with a chewier, more developed taste.
Can I substitute M&Ms with chocolate chips?
Yes! Chocolate chips are a great substitute if you prefer a more classic chocolate flavor without the candy shell. Feel free to mix in any chocolate variety you love.
What if I don’t have both quick oats and old fashioned oats?
You can use just one type of oats if necessary, but combining both gives the cookie a perfect balance of chewiness and rustic texture that makes the Monster Cookies Recipe so special.
How do I make sure my cookies stay soft and chewy?
Don’t overbake! Remove the cookies when the centers still look slightly shiny and soft. Also, chilling the dough and storing cookies properly help maintain their softness.
Final Thoughts
These Monster Cookies Recipe treats are pure joy baked into a cookie—rich peanut butter, hearty oats, and bursts of colorful candy that are sure to brighten any day. Once you try making and sharing these, they’ll quickly become your go-to recipe for both special occasions and everyday indulgences. So grab your mixing bowl and let’s bake some happiness!
Print
Monster Cookies Recipe
- Prep Time: 15 minutes
- Cook Time: 10 minutes
- Total Time: 25 minutes plus chilling time (1-3 hours or overnight recommended)
- Yield: 30 cookies
- Category: Dessert
- Method: Baking
- Cuisine: American
Description
Delightfully chewy Monster Cookies loaded with peanut butter, oats, and colorful M&Ms, creating the perfect sweet treat that’s both fun and satisfying. These cookies are soft in the center with a slight crisp on the edges and decorated with extra M&Ms and candy eyes for a playful twist.
Ingredients
Wet Ingredients
- 1 cup salted butter (softened, 2 sticks)
- 1 cup dark or light brown sugar
- 3/4 cup white sugar
- 1 cup peanut butter (creamy or chunky)
- 2 eggs
- 1 teaspoon vanilla
Dry Ingredients
- 1 & 1/2 cups flour (spooned and leveled)
- 2 teaspoons baking soda
- 1 teaspoon salt
- 1 cup quick oats
- 1/2 cup old fashioned oats
Add-Ins & Toppings
- 2 cups M&Ms (plus more for topping)
- Candy eyes (optional)
Instructions
- Beat Butter: In a large bowl or stand mixer, beat the softened butter for 2 minutes, scraping the sides and bottom to ensure even mixing.
- Add Sugars and Peanut Butter: Add the brown sugar, white sugar, and peanut butter. Beat until all ingredients are well incorporated and smooth.
- Incorporate Eggs and Vanilla: Add the two eggs and vanilla extract. Beat again thoroughly, scraping down the sides and bottom of the bowl to combine evenly.
- Mix Flour, Baking Soda, and Salt: Add the flour but do not mix it in yet. In a small bowl or using a spoon, stir the baking soda and salt into the flour until well combined. Then gently beat this mixture into the wet ingredients, leaving some streaks of flour for moisture and texture.
- Add Oats and M&Ms: Stir in the quick oats, old fashioned oats, and 2 cups of M&Ms carefully until just incorporated to avoid over mixing.
- Chill Dough: Cover the bowl and chill the dough in the refrigerator for 1 to 3 hours, or overnight for better flavor and easier scooping.
- Preheat Oven and Prepare Sheets: Once chilled, preheat the oven to 350°F (175°C). Line two baking sheets with silicone baking mats or parchment paper for non-stick baking.
- Scoop Cookies: Using a large cookie scoop, form dough balls about 2 inches across. Place the dough balls on the prepared baking sheets, spacing them at least 2 inches apart to allow for spreading.
- Bake: Bake the cookies at 350°F for 10 to 12 minutes, or until the centers are almost set but still shiny, and the edges have firmed up. Avoid over baking to maintain softness.
- Decorate and Shape: Immediately after removing from the oven, press additional M&Ms and candy eyes on top of each cookie. For taller, chewier cookies, push the edges slightly inward towards the center with a spoon.
- Cool: Let the cookies cool on the baking sheets for 5 minutes to set before transferring them to a wire rack to cool completely or enjoy warm.
- Store: Store cookies covered at room temperature for freshness and softness.
Notes
- Chilling the dough is essential for best texture and easier handling.
- Do not over bake; slightly underbaking keeps the cookies soft and chewy.
- Add candy eyes for a fun and decorative touch, perfect for parties or Halloween.
- Use a mix of quick oats and old fashioned oats for a great chewy texture.
- Peanut butter choice (creamy or chunky) affects the final texture subtly but both work well.
- For extra gooey cookies, eat them slightly warm out of the oven.

