Would you like to save this?
We'll email this post to you, so you can come back to it later!
Monster Cookies Recipe
This Monster Cookies Recipe bakes up big, chewy peanut butter oatmeal cookies absolutely loaded with chocolate chips and colorful M&Ms—perfect for bake sales, lunch boxes, and those “I just need something sweet” nights.
These classic chewy monster cookies are what happens when peanut butter cookies meet oatmeal cookies and crash into a bag of candy. You get soft and chewy cookies with crisp edges, chocolate in every bite, and a rainbow of M&Ms on top. This is a family friendly cookie recipe that feels nostalgic, looks bakery-style, and comes together with pantry staples. Around here, this is the homemade monster cookies recipe my grown kids still request whenever they’re home for a long weekend.
You can dress them up for holidays (red and green M&Ms at Christmas, pastels at Easter, team colors for game day) or keep them classic. Either way, this is an easy monster cookies recipe that you’ll come back to again and again.
Full Recipe Introduction
If you’ve never tried a Monster Cookies Recipe before, think of it as a “greatest hits” cookie. It has:
- Peanut butter richness
- Chewy oats for texture
- Lots of chocolate chips
- Plenty of M&Ms for color and crunch
No flour, big flavor, and a little bit of everything. It’s like the cookie version of a potluck table—everyone brings something, and somehow it all works.
I started baking these chewy monster cookies when my kids were in elementary school, usually for school parties or church events. I loved that they were crowd pleasing cookies that looked fun and colorful but still felt somewhat hearty from the oats and peanut butter. Over the years I’ve tested plenty of “best monster cookie recipe” claims, but I always come back to this version: thick, soft in the center, with just the right amount of candy.
A few things that make this Monster Cookies Recipe special:
- It uses both old-fashioned oats and quick oats for the perfect soft-and-chewy texture.
- The dough chills briefly, which gives you bakery style monster cookies that are thick and don’t spread all over the pan.
- There’s no flour, which gives them an almost fudgy, chewy bite—half peanut butter cookie, half oatmeal cookie.
I love to bake these on lazy Saturday afternoons, usually with a big cup of coffee and a podcast going in the background. They’re also one of my go-to “welcome to the neighborhood” treats because they travel well and feel fun and generous.
Why You’ll Love This Monster Cookies Recipe
- Soft and chewy, never dry – The mix of peanut butter, oats, and just the right bake time gives you soft and chewy cookies, even the next day.
- Loaded with goodies – Chocolate chips, M&Ms, and oats mean you get texture and flavor in every single bite.
- No flour needed – Classic monster cookie recipe style: these are naturally flourless when you use certified gluten-free oats and candies.
- Pantry-friendly ingredients – Everything in this easy monster cookies recipe is probably sitting in your kitchen right now.
- Perfect for kids (and grown-ups) – Bright, colorful candy cookies that grab attention at parties and bake sales.
- Freezer-friendly – You can freeze the dough balls or baked cookies for quick treats anytime.
- Customizable – Swap in peanut butter cups, mini chocolate chips, or seasonal M&Ms; make them your own.
- Bakery-style look at home – A simple trick of pressing extra M&Ms on top makes them look like they came from a fancy cookie bakery.
- Great for gifting – Thick, sturdy, crowd pleasing cookies that stack well in cookie tins and gift boxes.
Ingredients for the Best Monster Cookies
Here’s everything you need to make this homemade monster cookies recipe. I’ll include a few notes and substitution ideas, because I know we all run out of things at the worst moment.
Cookie Base
-
1/2 cup (1 stick, 113 g) unsalted butter, softened
Use room-temperature butter so it creams easily. Salted butter works too—just reduce the added salt a bit. -
1 cup creamy peanut butter
Use a regular shelf-stable peanut butter like Jif or Skippy. Natural peanut butter (the kind that separates) can make the dough too oily and crumbly, but I’ll share a workaround in the FAQs. -
3/4 cup packed light brown sugar
Brown sugar adds moisture and that caramel-like chew. -
1/2 cup granulated sugar
Balances the flavor and helps give a lightly crisp edge. -
2 large eggs, at room temperature
Cold eggs can make the fat seize up a bit, so let them sit out for 10–15 minutes if you can. -
2 teaspoons pure vanilla extract
Don’t skip this; it adds warmth and rounds out all that peanut butter and chocolate. -
1 teaspoon baking soda
Gives a bit of lift and keeps the cookies from being dense. -
1/2 teaspoon fine sea salt
If you’re using salted butter, reduce to 1/4 teaspoon.
Oats & Mix-Ins
-
1 cup old-fashioned rolled oats
These give structure and nice chewy bits. Don’t use steel-cut oats here. -
1 cup quick oats
Quick oats help the dough hold together and bake up tender. If you only have one kind of oats, use 2 cups of that and add 1–2 tablespoons more if the dough feels too soft. -
3/4 cup semi-sweet chocolate chips
You can use milk chocolate or a mix of chips if you like. Mini chips work well for a more even chocolate spread. -
3/4 cup M&M’s (plus a little extra for topping)
Regular, mini, or seasonal colors all work. Press a few extra on top of each cookie before baking or right after baking for that bakery-style monster cookies look. -
1/2 cup chopped peanuts or pecans (optional)
For extra crunch and that loaded peanut butter cookies vibe. Leave them out if you want a nut-free feel (beyond the peanut butter).
Step-by-Step Monster Cookies Recipe Directions
You don’t need any fancy skills for this M&M cookies recipe—just a bowl, a mixer, and a little patience while they chill.
-
Cream the butter, peanut butter, and sugars
In a large mixing bowl (or the bowl of a stand mixer), beat the softened butter, creamy peanut butter, brown sugar, and granulated sugar together on medium speed for about 2–3 minutes. The mixture should look lighter in color and a little fluffy. Scrape down the sides of the bowl once or twice so everything blends evenly. -
Add eggs and vanilla
Beat in the eggs one at a time, mixing just until combined after each addition. Add the vanilla and mix again. At this point, the batter should be smooth and glossy. If it looks broken or greasy, let it rest for a couple of minutes, then mix again briefly. -
Stir in baking soda and salt
Sprinkle the baking soda and salt over the top of the mixture and beat on low for about 10–15 seconds. This helps distribute the leavening evenly so you don’t end up with any bitter spots. -
Add the oats
Add the old-fashioned oats and quick oats to the bowl. Use a spatula or the mixer on low speed to fold them in just until there are no pockets of plain peanut butter mixture left. The dough will be thick. -
Fold in the chocolate chips and M&Ms
Add the chocolate chips and most of the M&Ms (reserve a small handful for pressing on top). Gently fold until they’re evenly distributed. Try not to overmix or you’ll break too many of the candies. -
Chill the dough (don’t skip this)
Cover the bowl and chill the dough in the refrigerator for 30–45 minutes. This helps the oats hydrate a bit and keeps the cookies thick and chewy instead of spreading thin. If your kitchen is warm, err on the longer side of chilling. -
Preheat the oven and prep the pans
When the dough is nearly chilled, preheat your oven to 350°F (175°C). Line 2 baking sheets with parchment paper or silicone baking mats. Parchment helps cookies bake evenly and makes cleanup easier. -
Scoop the cookie dough
Use a medium cookie scoop (about 2 tablespoons of dough) or roll the dough into balls by hand. Place the dough balls a few inches apart on the prepared baking sheets—these are bakery style monster cookies, so give them room. Gently press a few extra M&Ms onto the tops of each ball for that classic monster cookie look. -
Bake to soft-set
Bake one sheet at a time for 10–12 minutes, or until the edges are just set and lightly golden but the centers still look a bit soft and puffy. They’ll continue to set on the pan as they cool. If you like a softer, chewy monster cookie, stop closer to the 10-minute mark. -
Cool and enjoy
Let the cookies cool on the baking sheet for 5–10 minutes, then transfer to a wire rack to cool completely. If they came out slightly misshapen, you can nudge the edges with a spoon while they’re still warm to make tidy circles—little bakery trick.
Servings & Timing
- Yield: About 22–26 large cookies (using ~2 tablespoons dough per cookie)
- Prep Time: 20 minutes
- Chill Time: 30–45 minutes
- Bake Time: 10–12 minutes per batch
- Total Time: About 1 hour (a little longer if baking multiple sheets back-to-back)
If you’re baking for a party, you can easily double this Monster Cookies Recipe. Just use two baking sheets and rotate them in and out of the oven.
Fun Variations on Monster Cookies
Once you’ve made this classic monster cookie recipe, it’s easy to tweak it for seasons, allergies, or just for fun.
- Gluten-Friendly Monster Cookies – Use certified gluten-free oats and gluten-free candies; the recipe is naturally flourless already.
- Peanut-Free “Monster” Cookies – Swap the peanut butter for creamy almond butter or sunflower seed butter (SunButter) for a school-friendly version.
- Holiday Monster Cookies – Use red and green M&Ms at Christmas, orange and brown for Halloween, or pastel colors for spring.
- Monster Cookie Bars – Press the dough into a greased or parchment-lined 9×13-inch pan and bake at 350°F for 20–25 minutes; cool and cut into bars.
- Extra-Chocolate Monster Cookies – Add 2 tablespoons cocoa powder and use dark chocolate chips for a richer, deeper chocolate flavor.
- Mini Monster Bites – Use a small cookie scoop and bake for 7–8 minutes for cute, bite-sized colorful candy cookies.
How to Store and Freeze Monster Cookies
These cookies keep well, which makes them great for planning ahead.
Room Temperature
- Store completely cooled cookies in an airtight container at room temperature for 4–5 days.
- Place a small piece of bread in the container if you’d like them to stay extra soft; the cookies absorb a bit of the moisture.
Freezing Baked Cookies
- Freeze in a single layer on a baking sheet until solid, then transfer to a freezer bag or container.
- They’ll keep well for up to 2–3 months.
- Thaw at room temperature or pop one in the microwave for 10–15 seconds for a warm, soft cookie.
Freezing Cookie Dough
For the easiest “ready when you are” cookie stash:
- Scoop the dough into balls after chilling.
- Place on a parchment-lined sheet and freeze until firm.
- Transfer the frozen dough balls to a freezer bag, pressing out extra air.
Bake straight from frozen at 350°F, adding 1–2 extra minutes to the bake time. No need to thaw. This is my favorite make-ahead trick for busy weeks or last-minute guests.
Notes from My Kitchen (Little Things That Make a Big Difference)
- Underbake just slightly – The secret to truly soft and chewy monster cookies is to pull them when the centers still look a little soft. They’ll finish setting on the pan.
- Don’t skip the chill – I know it’s tempting, but chilling helps the oats soak up moisture and keeps the cookies thick instead of flat.
- Watch your peanut butter – Natural peanut butter can work, but you may need to add an extra 2–3 tablespoons of oats if the dough feels greasy. Regular creamy peanut butter is the most reliable for this best monster cookie recipe.
- Use a cookie scoop – A medium cookie scoop keeps all your cookies the same size, which means even baking and prettier gift boxes.
- Pan choice matters – Dark metal pans may brown the bottoms faster, so check a minute earlier. Light-colored aluminum pans give you a more even bake.
- Add toppings after baking (optional) – If some M&Ms crack or sink, you can gently press a few extra into the tops of the cookies right after they come out of the oven while they’re still soft.
If you love this recipe, you might also enjoy checking out other peanut butter chocolate chip cookies or oatmeal-based cookies on your site—they use very similar pantry ingredients and techniques.
FAQs About Monster Cookies
1. Can I use natural peanut butter in this Monster Cookies Recipe?
Yes, but the texture changes. Stir the natural peanut butter very well, then start with the written amount and add 1–3 tablespoons extra oats if the dough looks oily or too soft.
2. My cookies spread too much—what went wrong?
Most of the time it’s either warm dough or very soft (or melted) butter. Make sure you chill the dough at least 30 minutes and that your butter is just softened, not melted.
3. Can I make smaller cookies instead of big bakery-style ones?
Absolutely. Use a small cookie scoop, about 1 tablespoon of dough per cookie, and bake for 7–9 minutes. Keep an eye on them near the end; smaller cookies bake faster.
4. Can I make this recipe gluten-free?
Yes—use certified gluten-free oats and double-check that your M&Ms or chocolate candies are gluten-free. The recipe doesn’t use wheat flour, so it’s easy to adapt.
5. Can I reduce the sugar?
You can reduce the total sugar by about 1/4 cup without too much impact. The cookies may be a little less chewy and won’t spread quite as much, but they’ll still be lovely.
6. Are quick oats necessary, or can I use all old-fashioned oats?
You can use all old-fashioned oats if that’s what you have. The texture will be a bit heartier and more rustic; if the dough seems dry or crumbly, splash in a teaspoon or two of milk.
7. Why are my monster cookies dry or crumbly?
This can happen from too much oats (packed too tightly in the cup), overbaking, or using a very dry peanut butter. Next time, spoon the oats into the measuring cup and level off, and pull the cookies a little earlier.
8. Can I add other candies or mix-ins?
Yes! Chopped mini peanut butter cups, butterscotch chips, or even a handful of pretzel pieces make fantastic additions to these loaded peanut butter cookies. Just keep the total amount of mix-ins around 1 1/2–2 cups so the dough can still hold together.
Conclusion: A Cookie Jar Classic You’ll Make Again and Again
This Monster Cookies Recipe gives you everything you want in a treat: soft and chewy centers, crisp edges, peanut butter richness, hearty oats, and plenty of colorful chocolate candies. They look fun, taste nostalgic, and hold up beautifully for parties, game nights, and after-school snacks.
Give these homemade monster cookies a try this week—then come back and let me know how your family liked them. Leave a comment with your favorite variation, or explore more peanut butter oatmeal cookies and M&M cookies recipes on your site to keep your cookie jar happily full.
Monster Cookies
Ingredients
- 1/2 cup unsalted butter 1 stick (113 g), softened
- 1 cup creamy peanut butter use regular shelf-stable peanut butter like Jif or Skippy
- 3/4 cup light brown sugar packed
- 1/2 cup granulated sugar
- 2 large eggs at room temperature
- 2 teaspoons pure vanilla extract
- 1 teaspoon baking soda
- 1/2 teaspoon fine sea salt reduce to 1/4 teaspoon if using salted butter
- 1 cup old-fashioned rolled oats do not use steel-cut oats
- 1 cup quick oats can use all one type of oats if needed
- 3/4 cup semi-sweet chocolate chips mini or milk chocolate chips also work
- 3/4 cup M&M's plus extra for topping; regular, mini, or seasonal colors
- 1/2 cup chopped peanuts or pecans optional, for extra crunch
Instructions
- In a large mixing bowl or the bowl of a stand mixer, beat the softened butter, creamy peanut butter, brown sugar, and granulated sugar together on medium speed for 2–3 minutes, until lighter in color and slightly fluffy. Scrape down the sides of the bowl once or twice so everything blends evenly.1/2 cup unsalted butter, 1 cup creamy peanut butter, 3/4 cup light brown sugar, 1/2 cup granulated sugar
- Beat in the eggs one at a time, mixing just until combined after each addition. Add the vanilla extract and mix again until the batter is smooth and glossy.2 large eggs, 2 teaspoons pure vanilla extract
- Sprinkle the baking soda and fine sea salt over the top of the mixture and beat on low speed for about 10–15 seconds to distribute evenly.1 teaspoon baking soda, 1/2 teaspoon fine sea salt
- Add the old-fashioned oats and quick oats to the bowl. Use a spatula or the mixer on low speed to fold them in just until no streaks of plain peanut butter mixture remain. The dough will be thick.1 cup old-fashioned rolled oats, 1 cup quick oats
- Add the chocolate chips, most of the M&M's (reserve a small handful for topping), and chopped peanuts or pecans if using. Gently fold until evenly distributed, trying not to break the candies.3/4 cup semi-sweet chocolate chips, 3/4 cup M&M's, 1/2 cup chopped peanuts or pecans
- Cover the bowl and chill the dough in the refrigerator for 30–45 minutes to allow the oats to hydrate and to keep the cookies thick and chewy instead of spreading.
- Near the end of the chilling time, preheat the oven to 350°F (175°C). Line 2 baking sheets with parchment paper or silicone baking mats.
- Use a medium cookie scoop (about 2 tablespoons of dough) or roll the dough into balls by hand. Place the dough balls a few inches apart on the prepared baking sheets. Gently press a few extra M&M's onto the tops of each ball.3/4 cup M&M's
- Bake one sheet at a time for 10–12 minutes, or until the edges are just set and lightly golden while the centers still look soft and puffy. For softer, chewier cookies, bake closer to 10 minutes.
- Let the cookies cool on the baking sheet for 5–10 minutes, then transfer to a wire rack to cool completely. If desired, gently nudge the warm edges with a spoon to make them more evenly round before they set.
