
Monster cookies are peanut butter cookies with oats, chocolate chips, and M&Ms. My easy monster cookie recipe yields extra soft and thick cookies and you don’t need to chill the cookie dough!
For as much as I love peanut butter cookies and iced oatmeal cookies, I’ve never published a monster cookies recipe on my blog before. To be honest, the reason I’ve never shared one is because it’s taken me almost 3 months to develop one I’m proud enough to publish. Too flat, too puffy, falling apart, rock hard, too dry, and too sweet peanut butter oatmeal cookies have all made their way in my kitchen lately. But I’ve finally found that “perfect” one and I’m so excited to show you!
What Makes These Monster Cookies Different?!
My monster cookie recipe is unlike most traditional recipes. It’s more like a peanut butter cookie with oats, rather than an oatmeal cookie with peanut butter. Other aspects setting these monster cookies apart from the rest:
This recipe doesn’t make 5-6 dozen cookies like most monster cookie recipes requiring a hefty load of ingredients. Rather, my recipe uses a small amount of ingredients and yields 2.5 dozen medium-sized cookies. They aren’t actually “monster” in size, but feel free to roll them larger. Or try my one giant monster cookie recipe if you want a literal monster-sized cookie!
And if you need a gluten free option, try these flourless monster cookies.
Quick Oats are Key
Use quick oats. Why? Quick oats are more finely cut whole oats and will give the monster cookies a more uniform texture. Furthermore, quick oats will act more as a binder since the consistency is more powdery. If you don’t have quick oats, pulse your whole oats in the food processor a few times to break them down.
Helpful tip: The cookies spread just slightly while baking, so press them down with a spoon after you remove them from the oven. That’s what gives the cookies their crinkled tops.
Quick Monster Cookies: No Dough Chilling!
Like I mentioned, this is a quick cookie recipe. Unlike your classic chocolate chip cookies or sugar cookies, there is no dough chilling needed for these monster cookies! The dough is thick and sturdy enough to bake right away. However, should you bake the monster cookies with a thinner peanut butter or on a particularly humid day, chill in the refrigerator for up to 30 minutes. Cookie dough can be picky. Go by how your dough feels. If it’s too sticky, chill for 30 minutes. If not, just bake.
Here are more no dough chilling cookie recipes. I have tons! Snickerdoodles and shortbread cookies are two favorites.
This recipe also joins 30+ others in my collection of Quick Dessert Recipes—ready in 1 hour or less!
These cookies remain exceptionally soft for days… if they last that long. I also find that the peanut butter flavor is intensified after day 1, too. Just like my favorite soft and thick peanut butter cookies and peanut butter chocolate chip cookies. Now wait until your first bite!

Soft-Baked Monster Cookies Recipe
Ingredients You’ll Need
Instructions
- Preheat oven to 350°F (177°C). Line baking sheet with parchment paper or silicone baking mat.
- In a large bowl, using a hand-held mixer or stand mixer with paddle attachment, cream the butter and sugars together on medium speed, about 3 minutes. Mix in the peanut butter, egg, and vanilla (in that order). Scrape down the sides of the bowl as needed. Slowly mix in the baking soda, flour, and salt. Do not over-mix. On low speed, beat in the quick oats, M&Ms, and chocolate chips just until incorporated. If the dough is very soft and unmanageable by hand, chill the dough for 30 minutes before rolling.
- Rolls balls of dough, about 2 Tablespoons of dough per ball, onto prepared baking sheet. Press a few extra M&Ms on top for looks, if preferred. Bake for 11-13 minutes—the cookies will still look a little soft, which is recommended. Slightly press down the baked cookies with the back of a spoon, since the cookies only slightly spread in the oven. Allow cookies to cool on baking sheet for 10 minutes before transferring to a wire rack. Cookies will firm up as they cool.
- Store cookies covered at room temperature for up to 1 week.