Buttery M&M Peanut Butter Cookie Bars. These delicious cookie bars come together in minutes and are filled to the brim with peanut butter, M&M candy and chocolate chips.

Calling all peanut butter lovers!
I have a buttery treat for you! These M&M Peanut Butter Cookie Bars are loaded with creamy peanut butter and stuffed with M&M’s AND chocolate chips.
This delicious cookie bar combines three of my favourite things – cookies, peanut butter, chocolate and candy – oh, wait. Make that four!

You’ll be pleased to know these M&M Peanut Butter Bars take only minutes to make. There’s no need to chill the dough so they are ready to eat in under an hour.
The cookie dough is extra buttery and creamy thanks to the peanut butter and the M&M candy adds a lovely crunch, along with melty chocolate chips dotted throughout the entire thing.

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How to make M&M Peanut Butter Cookie Bars
- These cookie bars are so easy to make. There’s no need to chill the dough so they are ready in under an hour. You will need an electric mixer for this recipe.
- Start with room temperature butter. It should be soft to the touch but not melty by any means. Beat together your butter and brown sugar until combined and creamy – should take just a minute or two.
- Next, add your vanilla and peanut butter. I recommend using a full fat processed peanut butter for this recipe rather than a natural-style one (such as Bega, Skippy or Jif).
- Then, add your egg. Your mixture should be nice and creamy now. Finally, add your flour, baking powder and salt and mix together until a soft cookie dough forms.
- Then it’s time to add your mix-in’s. Throw in plenty of chocolate chips and M&M’s.
- Transfer your cookie dough to an 8-inch square baking pan lined with baking or parchment paper. And bake in the oven for approximately 28-30 minutes or until golden on the edges.
- Leave cookie bars to cool completely in the baking tin, before removing and slicing into squares to serve.

More peanut butter recipes to try
- Peanut Butter Chocolate Cookies
- Peanut Butter Blondies
- Peanut Butter Cake
- Peanut Butter Oatmeal Cookies
- Peanut Butter Sheet Cake

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Let’s Bake
M&M Peanut Butter Cookie Bars
Buttery cookie bars made with peanut butter and stuffed with M&M’s and chocolate chips.
Ingredients
- 115 grams (1/2 cup or 1 stick) unsalted butter, room temperature
- 180 grams (1 cup) brown sugar
- 1 teaspoon vanilla extract
- 125 grams (1/2 cup) smooth peanut butter*
- 1 large egg
- 175 grams (1 and 1/4 cups) plain flour or all purpose flour
- 1/2 teaspoon baking powder
- 1/4 teaspoon salt
- 75 grams (1/2 cup) chocolate chips
- 150 grams (3/4 cup) M&M’s
Instructions
- Preheat oven to 180 C (350 F) standard / 160 C (320 F) fan-forced. Grease and line an 8-inch square pan with baking or parchment paper.
- In a large mixing bowl, beat the butter and sugar with an electric mixer until pale and creamy. Add vanilla and peanut butter and mix briefly to combine.
- Add egg and continue to mix until soft and creamy. Sift in flour, baking powder and salt. Gently fold until the dough starts to come together.
- Throw in the chocolate chips and M&M’s and fold through. Place all the dough into your prepared tin and press down and spread out as evenly as possible using the back of a spoon or a small spatula.
- Place in the oven for 28-30 minutes or until golden brown. Remove from the oven and leave to cool completely in the cake pan before cutting into squares.
Notes
Peanut butter: I tested this recipe with processed peanut butter, such as Bega, Jif or Skippy. I recommend it over a natural-style peanut butter that has a more oily texture.
Nutrition Information

This recipe was first published on Sweetest Menu in March 2016.
Hafsa Ahmad says
Would these be possible to make with cookie butter instead of peanut butter? What adjustments would we need to make for that?
Jessica Holmes says
I haven’t tested it myself but I think it would work! Let me know if you try it.
Gillian says
I am only 10 and I use this website for everything.This is the best this yet!
Jessica Holmes says
Love hearing that Gillian!
Ashley says
If I wanted to halve this recipe, would you suggest just using the egg YOLK? Any suggestions for a 8×4 loaf pan?
Jessica Holmes says
Hi Ashley, I haven’t tested the recipe in another quantity. You can freeze half the cookie dough and bake it at a later date though if you like.
Michael says
Do you know if this recipe would be good substituted with gluten free flour?
Jessica Holmes says
Hi Michael! Sorry I haven’t tried this myself so I can’t say for sure. Hope you get to try them ☺️
ben says
I just made these and used Peanut Butter M&Ms omg soooooog good!
Jessica Holmes says
Awesome! So glad you enjoyed them Ben! 🙂
Lj says
I just made these and they are amazing and so easy to make only using one bowl as well so no hassle when cleaning up.
Jessica Holmes says
Thank you so much for the lovely feedback! I’m so glad you enjoyed them! 🙂
Lynn @ Fresh April Flours says
How can you resist a cookie bar filled with m&m’s? So simple and so cute and SO DELISH!
Jessica Holmes says
I can’t! Hahaha 🙂
Amanda says
These are the kind of bars that I grew up with in Minnesota. It’s dangerous for me to see these because now I’m going to want them every week! And I am definitely going to make them with the peanut butter M&Ms. Yum!
Jessica Holmes says
Aw thanks Amanda! 🙂
Jessica Holmes says
These sound so delicious! I love how quick and easy they are to whip up as well – definitely my kind of recipe. xx
Jessica Holmes says
So easy Lucy! 🙂
Amy says
Yes Jess, yes! Oh this sounds like heaven to my PB loving little heart 🙂 And I’ve seen some PB m&ms floating around a few different stores lately so I might have to treat myself this Easter to a big ole slice of heaven!
Jessica Holmes says
Oooh I love PB M&M’s! You’ll have to snag them when you see them!
Kathy says
My husband and kids will be begging me to bake this!
Jessica Holmes says
Hahaha I hope you get to try it Kathy!
Mary Ann says
I’ve died and gone to peanut butter heaven! It’s like one big over the top peanut butter cookie! Cannot wait to try Jess!
Jessica Holmes says
Aww thanks Mary Ann!
Melissa says
Yes, I am hungry, and yes, I want to make these right now! Salivating all over the place! (Just kidding. I am not slobbering like a dog. But I’m having to hold it in :))
Jessica Holmes says
Thanks Melissa! Hahaha!
Marsha says
Oh my, these bars look so good! I love peanut butter and M&Ms!
Jessica Holmes says
Me too Marsha!
Leah says
Yes! All of the peanuts/peanut butter! These look amazing, Jess. I’ll definitely have a whip a batch of these up for my peanut butter living husband (and for myself, duuh).
Jessica Holmes says
Thanks Leah! I hope you love them! 🙂