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Monster Cookie Bars

Skip the endless batches of cookies! Just press all of the dough into the pan and make a batch of these super easy Monster Cookie Bars stuffed with peanut butter, oats, and candies!
Monster Cookie Bars Recipe from A Kitchen Addiction
*This recipe was originally posted on 02/25/13.

Whoever decided to take their cookie dough, press it in a pan, bake it, and call it a cookie bar was smart. Now when you want a cookie, but you don’t want to deal with shaping them, doing multiple batches, etc.

You can just stick the dough in a pan, bake it, and 10-15 minutes later have your cookie craving satisfied! Which is good when monster cookie bars are involved!

Monster Cookie Bars Recipe from A Kitchen Addiction

When it comes to making monster cookies, it’s not that I don’t have the patience to wait for shaping, baking, etc., it’s that the longer the dough sits in front of me, the more I eat (what is it about peanut butter and oats that is so good?)!

Though I suppose that’s not always a bad thing. . . You have probably noticed that monster cookies are a favorite around here. We have monster cookies, monster cookie pie, monster cookie granola bites, etc.

It’s about time that I shared this easy recipe for monster cookie bars!

Easy Monster Cookie Bars Recipe from A Kitchen Addiction

These cookie bars contain my favorite cookie combination of oats, peanut butter, and chocolate. (And just because peanut butter is so good, I’ve added in some peanut butter chips!)

Feel free to use your favorite kind of chocolate chips. I used a mixture of milk chocolate and semi-sweet to get a couple of different flavors of chocolate into these bars. I also used mini M&M’s, because they make it seem like there are lots of M&M’s in your cookie bars without going overboard!

Next time you want cookies, but don’t have the time, give these cookie bars a try!

Monster Cookie Bars Recipe from A Kitchen Addiction

Monster Cookie Bars

Yield: 16 cookie bars
Prep Time: 15 minutes
Cook Time: 15 minutes
Total Time: 30 minutes

Skip the endless batches of cookies! Just press all of the dough into the pan and make a batch of these super easy Monster Cookie Bars stuffed with peanut butter, oats, and candies!


  • 1/4 Cup butter, softened
  • 3/4 Cup no-stir natural peanut butter (creamy or chunky depending on preference)
  • 1/2 Cup brown sugar
  • 1/4 Cup sugar
  • 1 egg
  • 1 teaspoon vanilla extract
  • 3/4 Cup all-purpose flour (can also use white whole wheat flour)
  • 1/2 teaspoon salt
  • 1/2 teaspoon baking soda
  • 1/2 Cup quick cooking oats
  • 1/2 Cup mini M&M's
  • 1/2 Cup chocolate chips (I used a mixture of milk and semi-sweet)
  • 1/4 Cup peanut butter chips


  1. Preheat oven to 350 degrees Fahrenheit. Lightly spray a 9x9 inch baking dish with non-stick cooking spray.
  2. In the bowl of a stand mixture, beat together butter and peanut butter until smooth. Add in sugars and beat until well-combined. Add in egg and vanilla extract and beat until smooth.
  3. In a small bowl, whisk together flour, salt, and baking soda. Slowly add flour mixture to wet ingredients and beat until combined. Stir in oats.
  4. Add in M&M's, chocolate chips, and peanut butter chips. Stir until just combined.
  5. Press dough into the bottom of prepared baking dish.
  6. Baked for 12-15 minutes or until edges start to turn golden brown and center is set.
  7. Allow to cool for 15-20 minutes and then cut into bars. Store leftovers in an airtight container.


This recipe can be easily doubled to fit a 9x13 inch baking dish.

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Nutrition Information:
Yield: 16 Serving Size: 1 cookie bar
Amount Per Serving: Calories: 242Total Fat: 14gSaturated Fat: 5gTrans Fat: 0gUnsaturated Fat: 7gCholesterol: 20mgSodium: 190mgCarbohydrates: 27gFiber: 2gSugar: 17gProtein: 5g

Nutrition information shown is an estimate provided by an online calculator and may not always be accurate. It should not be considered a substitute for a medical professional’s advice.

Did you make this recipe?

Please leave a comment or rating on the blog to let us know or share a pic on Instagram and tag @akitchenaddiction

This recipe is adapted from The Baker Mama.

Quick and Easy Monster Cookie Bars Recipe from A Kitchen Addiction



Monday 22nd of August 2016

These look so thick and delicious and I love your new site design!


Wednesday 18th of May 2016

I knew "monster cookies" as being the all-oat, no flour cookies (if you google it, that's a common trait of many of the recipes, along with peanut butter/M&Ms/chocolate chips of course). BUT, the all-oat monster cookies have never been a favorite of mine. I tried your Monster Bar recipe side-by-side with a popular all-oat version, and definitely preferred yours. I love oats, but in their proper place. :-) Yours struck a good balance between oats and flour. Thanks for posting!

Jessica@A Kitchen Addiction

Thursday 19th of May 2016

I'm so glad you liked them! Thanks for letting me know!

Ashley | The Recipe Rebel

Tuesday 5th of April 2016

Well I am glad these made a reappearance on the blog! They look INCREDIBLE -- I can't resist anything Monster Cookie!

Laura @ Laura's Culinary Adventures

Tuesday 5th of April 2016

I have never made monster cookies before. That needs to change soon! These bars look so chewy!


Tuesday 5th of April 2016

I've loved monster cookies since I was a kid---can't wait to try your easier bar cookie version!

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