Monster Cookie Bars have all the peanut buttery, chocolatey, chewy goodness of the traditional cookie, only in super easy bar form.
I have a well-established love of bars and bar cookies.
From Peanut Butter Cookie Bars to Apple Blondies, Brownies to fruit-filled Pie Bars, and oh my heart and happy taste buds, Cheesecake Bars too – they all make me happy both because they’re absolutely delicious and they’re so very easy to make!
Salty sweet graham cracker toffee is perfect for snacking on its own or crumbling over ice cream.
Monster Cookie Bars
Bars are so much easier and quicker to make than cookies. Cookies can be finicky; they need perfect ratios of flour, sugar, and butter, or they will spread flat or won’t spread at all.
With bars, there is a lot more leeway. With sides on a pan, the dough can’t go anywhere, not to mention it saves all the time rolling, and chilling, and baking individual cookie sheets of dough.
These are just perfect for an afternoon snack with a cold glass of milk. And luckily, it only takes a few minutes to stir a batch together.
My boys absolutely love these and they’ve become a serious favorite over the years.
One hour max start to finish, even if you have to Google how to crack an egg first. What excuse do you have for not making them?
How to make Monster Cookie Bars
These soft and chewy monster bars are easy to make!
Simply cream the butter and sugars together, beat in peanut butter, eggs, and vanilla and stir in the dry ingredients.
Last of all, you’ll fold in some chocolate chips and M&Ms. Press the monster cookie dough into a 9 x 13 pan and bake.
As hard as it is to wait, try to let them cool completely before slicing them into bars.
For a few more chocolate and oatmeal dessert combinations to try, don’t miss these Cranberry White Chocolate Oatmeal Cookies and the Chocolate Revel Bars.
These Double Decker M&M Brownies from Whisking Up Yum are calling my name now too!
Monster Cookie Bars
Ingredients
- ½ cup butter softened
- 1 cup brown sugar
- ½ cup peanut butter
- 2 eggs
- 1 tsp vanilla
- 1¾ cup all purpose flour
- 1 tsp baking soda
- 1¾ cup quick cooking oats
- ¾ cup semi-sweet chocolate chips
- 1 cup M&Ms
Instructions
- Preheat oven to 350 F. Grease a 9 x 13 pan and set aside.
- In a large bowl, cream together butter and brown sugar. Beat in peanut butter, eggs and vanilla.
- In a separate bowl, stir together flour, and baking soda. Add to large bowl and stir until combined. Add oats, chocolate chips and M&Ms.
- Press into greased pan. Add additional M&Ms to the top, if desired, pressing them into the dough slightly.
- Bake for 14 – 16 minutes or until edges are slightly brown or until toothpick inserted comes out clean. Do not over bake. Let cool a bit before slicing. Letting them cool completely is best. But its almost impossible to wait that long.
Notes
Nutrition
{originally published 8/19/14 – recipe notes and photos updated 1/4/21}
Melanie @ Carmel Moments says
Mmm….I love me a good cookie bar. Looks like a perfect snack to share too.
Pinned.
Mallory says
Thanks, Melanie!
Taylor @ Food Faith Fitness says
Cookie bars are THE best because they are so easy….which also makes it easier to whip up a batch and eat the whole thing. Not that I’ve done that…
Love these! Pinned!
Cindy (Vegetarian Mamma) says
Seriously drooling! LOVE!
DessertForTwo says
I’m all about bars over cookies! So much faster and just as good! 🙂
Kelly @ Mostly Homemade Mom says
I seriously LOVE making cookies in bar form, too! These look great and so fun!
Amanda says
What a fun dessert!
Karly says
These cookie bars are right up my alley! I love them!
Thalia @ butter and brioche says
i wish that i had one of these cookie bars right now.. they look so delicious!
Jocelyn@Brucrewlife says
Give me a few of these delish bars, a big cup of milk, and I’m good to go!! 🙂 They look amazing!
Sally says
These just came out of the oven…they look amazing! Looks like they will be on the gooey side? If so, double YUM. Thanks for sharing!
lisa g. says
These look very good! Does the oatmeal dry out the cookie bars? Thank you!
Mallory says
No, not at all. They are soft and delicious!
Ryann says
Hello, can I omit the peanut butter? Can I replace it with something else. or just leave it out all together?
Melissa says
Will steel cut oats work the same? Thanks!
Mallory says
Not sure. But I would stick to rolled or quick pats.
Sara says
These bars are delicious! But I almost never have quick oats on hand, do you think regular rolled oats would work as well?
Mallory says
Yes. Rolled oats would be fine in this recipe. You could also pulse rolled oats in the blender or food processor to make quick oats.
jess says
What does it mean to cream the butter?
Mallory says
Beat them sugar and butter together with a mixer or wooden spoon until well incorporated and fluffy.
Malissa says
Can you use sun butter instead of peanut butter?
Mallory says
I’ve never worked with sun butter, but if you try it, let us know how it works! Happy Baking!
Bridget says
Any suggestions for a substitute for egg?
Amy says
Can I double this and bake in a jelly roll pan?
Mallory says
I have never tried it, but I think it would work.
Karissa says
Gooey & delicious! I used a 9×9 pan so I baked them for a little longer. I used peanut butter M&Ms and mini chocolate chips and these turned out great!
Mary says
I’m so glad you liked them, Karissa.
Ana Agundez says
I followed the directions and all I got was a dry flour mixture. I went over the directions three times and cannot find my mistake.
Mary says
Without being in your kitchen with you, it’s hard to guess what might have gone wrong, Ana. By chance were you scooping and or shaking your flour vs spooning it into the cup and leveling it off? That’s the most common way that too much flour is added to baked goods. (And that may have created a drier dough for the recipe.)
Cari says
These were good BUT the amount of salt is to much. It almost makes the cookie bars inedible. Next time I will reduce the amount to 1/4 tsp.
Mary says
Oh my goodness, I am so sorry about that, Cari! That was a mistake in the recipe. I typically make these either with salted butter or just add a pinch of salt to the recipe. I switched over my recipe cards a while back and somehow the measurements were messed up. I’m glad they were still edible – albeit too salty!
Bella says
Does the recipe not call for white sugar? Just wanting to make sure before I make it!
Mary says
It does not. Brown sugar only.
Erica says
Came together easily but very crumbly, may need to add more liquid! Delicious!
Mary says
hmmm. You might double-check your measurements. I have not had any issues.
Lindsay says
Too dry! I would use less flour and Oats
Mary says
To each their own. Feel free to customize to suit your tastes, Lindsay.
Jessica says
Could you make the batter the night before and store in the fridge before needing to bake them?
Mary says
You could do that, Jessica.
Brooke says
How much salt??
Mary says
Hi Brooke, I use salted butter to make this recipe. If you prefer to use unsalted butter, you might want to add a pinch of salt to this recipe.
Julie McDonough says
I made a double batch. I used all natural peanut butter instead of regular peanut butter. The bars were nice and chewy but fairly bland and dry. Felt like they were missing something. I ended up grinding some pink Himalayan sea salt on top to give it a little more depth of flavor.
Mary says
Hi, Julie! If you used all natural peanut butter as a substitute, that’s probably why the bars were dry afterward. All natural peanut butter tends to be slightly thinner and more watery, which can result in slightly drier baked goods. Using Himalayan sea salt sounds like a great idea, though, and I’ll bet it worked well as a substitute. Enjoy the bars, and I hope your next batch turns out better than the first. Happy baking!
Kelly Wiggins says
can these be made a head of time and freeze them and take them out when it’s time.
Mary says
You should be able to prep these in advance, Kelly. They should keep on the counter for a day or two; I’d recommend refrigerating or freezing beyond then, depending on how far in advance you’re going to prep.
Kelly Wiggins says
I”m making these for Christmas and i freezer my other cookies like a week or two weeks a head of time then i take some out when i need them.
Megan says
These are super easy to make and so delicious. My family loves monster cookies and these are even better!
Mary says
YAY! I’m glad you’re enjoying the recipe, Megan.