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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
Nutrition information is automatically calculated, so should only be used as an approximation.
{originally published 8/19/14 – recipe notes and photos updated 1/4/21}
These are super easy to make and so delicious. My family loves monster cookies and these are even better!
YAY! I’m glad you’re enjoying the recipe, Megan.
can these be made a head of time and freeze them and take them out when it’s time.
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.
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.
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.
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!
How much salt??
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.
Could you make the batter the night before and store in the fridge before needing to bake them?
You could do that, Jessica.
Too dry! I would use less flour and Oats
To each their own. Feel free to customize to suit your tastes, Lindsay.
Came together easily but very crumbly, may need to add more liquid! Delicious!
hmmm. You might double-check your measurements. I have not had any issues.
Does the recipe not call for white sugar? Just wanting to make sure before I make it!
It does not. Brown sugar only.