Monster cookies are the cookie I grew up on. My mom made them every Christmas and now my own kids ask for them by name. They are thick, chewy, and packed with peanut butter, oats, chocolate chips, and M&M's. No flour in the dough, so they are naturally gluten-free, and the batch is big enough to share.
The best part is how easy they are to dress up for any holiday. Swap in red and green M&M's for Christmas, orange and brown for Halloween, pastels for Easter. Same dough, different season.
Why These Monster Cookies Work
No flour means no gluten, but it also means the oats and peanut butter do all the work. Old-fashioned oats give these cookies their hearty, chewy bite. Quick oats work in a pinch, but the texture comes out softer and less substantial.
Dark brown sugar is worth it here. It has a deeper caramel sweetness that holds its own against the peanut butter and chocolate. Light brown sugar works, but the flavor is flatter.
The dough goes straight from the mixer to the baking sheet. No chilling, no waiting. For a big batch cookie, that matters.
Pull them when the edges are browned and the centers still look soft. They finish baking on the hot baking sheet as they cool. Overbaking is the only way to ruin a monster cookie.
How to Make Monster Cookies
- Preheat the oven to 350°F and line your cookie sheets with parchment paper.
- Cream the softened butter, peanut butter, granulated sugar, and dark brown sugar together until smooth. A stand mixer makes quick work of this, but a hand mixer gets the job done too. Beat in the eggs and vanilla.
- Add the old-fashioned oats and baking soda and beat until combined. Then mix in the chocolate chips and M&M's on low speed, scraping down the sides of the bowl so everything is evenly distributed.
- Scoop the dough by a tablespoon and a half, or use a number 40 cookie scoop, and place the dough balls two inches apart on the prepared baking sheets.
- Bake for 11 to 13 minutes. The edges should be golden brown but the centers will still look soft and slightly underdone. That is exactly what you want. Let the cookies rest on the baking sheet for 5 minutes before moving them to a wire rack to cool completely.
Quick Tips
- Use room temperature butter and eggs so everything creams together smoothly.
- Old-fashioned oats give the chewiest texture. Quick oats will make a softer cookie.
- Do not overbake. Soft centers are the whole point.
- Dark brown sugar over light brown for a richer flavor.
- Swap the M&M colors to match the holiday. Nothing else in the recipe changes.
Make Ahead and Storage
Let the cookies cool completely before storing so the chocolate has time to set. Stacking warm cookies is how you end up with a sticky mess. Once cooled, keep them in an airtight container on the counter for up to 5 days.
These cookies freeze beautifully. Lay them in a single layer in a freezer-safe bag and freeze for up to 3 months. Label the bag so you know what is in there.
They also ship well. Sturdy cookies, a tin, and wax paper between the layers is all you need.
More Cookie Recipes
For more holiday baking, browse my Christmas cookie recipes. My chocolate espresso cookies use brown butter and dark chocolate, and my toffee cookies are crisp and buttery.
📖 Recipe
Monster Cookies (Gluten-Free Option)
Ingredients
- 1 cup dark brown sugar
- 1 cup granulated sugar
- 2 teaspoons baking soda
- 4 ½ cups old fashioned oatmeal - *
- ½ cup unsalted butter - softened
- 1 cup peanut butter
- ¼ teaspoon vanilla extract
- 3 eggs
- 11.5 ounce bag chocolate chips*
- 11 ounce bag M&M's
Instructions
- Preheat oven to 350°F and line cookie sheets with parchment paper.
- Combine softened butter, peanut butter, granulated sugar, brown sugar, vanilla, and eggs in a mixing bowl and beat until creamy.
- Slowly add the oatmeal and baking soda to the wet mixture and beat until combined.
- Stir in the chocolate chips and M&M's, until evenly distributed in the cookie dough.
- Scoop cookies by 1 and a half tablespoons or use a #40 cookie scoop to portion the cookie dough and place them onto the prepared cookie sheets two inches apart.
- Bake for 11 to 13 minutes, let them cool for 5 minutes before transferring them to a cooling rack to cool completely.
- Store in an airtight container.
Notes
- Use old-fashioned oats for the chewiest texture. Quick oats make a softer cookie.
- Dark brown sugar gives a richer flavor than light brown.
- Do not overbake. Pull the cookies when the centers still look soft. They set as they cool.
- Cool completely before storing so the chocolate sets.
- Freeze for up to 3 months in a freezer-safe bag. Ship in a tin with wax paper between layers.
- Swap M&M colors for any holiday.
Nutrition
Nutritional information is an estimate based on third-party calculations. Actual values may vary due to ingredients, measurements, and serving sizes.
© Mama Needs Cake
Tried this recipe?
Let us know how it was!Dana is an experienced recipe creator who crafts easy and delicious recipes for all levels of home cooks.
Her recipes range from classic comfort foods to healthy and nutritious meals, and she is always on the lookout for new and exciting ways to bring flavor and variety to the table.
These look so good! We will have to try some soon!
These look delicious to make with my little boy!!!
Oh my gosh ! It’s 10pm I’m up working and all I want are these cookies now! Definitely going to have to give these a try with my three year old
my son would love it!
I love the name and how easy they seem to be to make. I am NOT a baker more of a cook. But these look simple enough!
Ok these cookies are flat out awesome! Made them just as the recipe said and they're fantastic! My 11 year old daughter, who is big into baking right now, and I had a lot of fun making these. Thanks for sharing this with everyone!
Ok these cookies are flat out awesome! Made them just as the recipe said and they're fantastic! My 11 year old daughter, who is big into baking right now, and I had a lot of fun making these. Thanks for sharing this with everyone!
So happy to hear that you guys enjoyed them! Love that your daughter is into baking right now! <3
Can you tell me which type of oatmeal works the best for these?
I used old-fashioned vs. quick oats because the cookies have more texture with the old-fashioned. How that helps!
Yes thanks!!!!!
My cookies are coming out completely flat. Is that normal? I'm frustrated cause I followed all the steps and idk when I could have gone wrong
Your butter may be a little too soft. You can chill the dough for about half an hour to prevent the cookies from spreading in the oven.
For some reason the cookies do not seem like they are done within the time frame it says which results in the bottom coming out a little burnt. Help.
Hi Isabella,
The cookies should be soft in the middle. They still continue to bake once they are taken out of the oven.
Our neighbor, Kristin, sent these delicious cookies over earlier this month. She knows I like to freeze dough, and bake later. Kristen put dough balls in a ziploc freezer bag with a note on the bag of what to. I just baked these this morning, and they are delicious! I'm adding them to my baking recipes and sharing your site on my facebook page. Thank you for sharing these!
Our neighbor, Kristin, sent these delicious cookies over earlier this month. She knows I like to freeze dough, and bake later. Kristen put dough balls in a ziploc freezer bag with a note on the bag of what to. I just baked these this morning, and they are delicious! I'm adding them to my baking recipes and sharing your site on my facebook page. Thank you for sharing these!
Hi Kathy! I am so happy to hear that you enjoyed these cookies!
Amazing cookies!! I used chocolate chips and butterscotch chips instead of M&Ms, and only used about 1/2 bag of each and they turned out perfect. The dough seemed wet but the cookies didn’t spread too much, 13 minutes cook time was perfect. Once I took the cookies out of the oven and they cooled a little the middle looked a little wet, but they were cooked to perfection. Highly recommend!
Amazing cookies!! I used chocolate chips and butterscotch chips instead of M&Ms, and only used about 1/2 bag of each and they turned out perfect. The dough seemed wet but the cookies didn’t spread too much, 13 minutes cook time was perfect. Once I took the cookies out of the oven and they cooled a little the middle looked a little wet, but they were cooked to perfection. Highly recommend!
Hey Jackie! Yup, they're supposed to look underbaked in the center... that's how you get that incredibly soft and chewy cookie! I'm so happy to hear that you enjoyed them!
Can you freeze the dough? If so does it change the taste? Also, should I thaw them before baking or bake the frozen?
Yes, you can! I'd recommend scooping the dough and then freezing the dough balls in an airtight container. If stored properly the taste should not change. No need to thaw the dough first, just keep an eye on the cookies at the end of the baking time. 🙂
Can you use less sugar ?
Yes, you can use reduce the amount of sugar in this recipe but it may alter the chewiness of the cookies, especially the brown sugar. 🙂