The BEST soft, thick, and chewy M&M cookie bars for any occasion! Bake in a standard 9x13 pan for a quick & easy after-school treat, birthday cookie cake, or add seasonal M&M's to match any holiday!
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Your New Go-To Cookie Bars for ANY occasion!
- Make for an easy after-school treat, summer barbecue, or quick potluck dessert!
- Use different colored M&M's for Christmas, Valentine's Day, 4th of July, or Easter M&M bars!
- Perfectly durable, chewy squares to use for summer homemade ice cream sandwiches!
- Add frosting and sprinkles for a easy 9x13 birthday homemade cookie cake!
- Don't have M&M's? Replace them with another ½ cup of chocolate chips for chewy chocolate chip bars!
What You Need to Make Easy M&M Cookie Bars From Scratch
- Unsalted Butter
- Granulated Sugar + Brown Sugar
- 1 Egg
- Vanilla Extract
- Baking soda + Baking Powder
- Flour
- Semi-Sweet Chocolate Chips
- M&M's
How to Make Chewy M&M Cookie Bars
Step 1: Mix Dough by Hand
In a small microwave-safe bowl, melt the butter for 20-30 seconds until JUST melted (you don’t want it piping hot and don't want any unmelted chunks).
- Transfer melted butter to a larger mixing bowl and add in white sugar and brown sugar.
- Use a spatula (don’t use a mixer!) to stir by hand until combined. Mix in egg. Next, add in baking soda, baking powder, and salt and mix again. Add flour.
- Mix until all the flour disappears into the dough.
- Lastly, add the ½ cup of chocolate chips and ½ cup of M&M's into the dough and mix. I mean, does it get any better than chocolate chip AND m&m cookie bars? I think not. These truly are the best m&m cookie bars.
Step 2: Press Dough Into Pan
Grease a 9x13 pan or line with parchment. Use a spatula or your hands to press down the dough into a smooth layer (being sure to get all the corners).
Step 3: Bake
Bake at 350 degrees for 14-15 minutes – do NOT overbake or your M&M cookie bars will not be soft. If desired, right after baking immediately press extra M&M's in the top.
How do you know when the M&M bars are done? The top should be slightly brown (see below) and the center baked through. The cookie bars may still look slightly underbaked but this is the trick to a soft, chewy cookie. If you overbake it and it gets too brown, you will have crunch M&M cookie bars. For the best slices, allow the cookie cake to cool completely before cutting & removing.
Step 4: Cut into Squares
Use a sharp, large knife to cut. Depending on how many you’re needing to feed, cut the bars in smaller or larger squares.
Frequently Asked Questions:
Can I freeze these M&M cookie bars?
Yes! These are actually really good frozen, straight-from-the-freezer. Although freezing cookies will usually dry them out a bit (i.e. won't be as chewy), if you do need to make this in advance, wrap the cut baked bars in plastic wrap then place in a airtight bag or container. When you’re ready to eat, let it thaw to room temperature (or just eat frozen...my fave!).
If you've got a good airtight plastic container, that will also work for freezing...although I find that they absorb a little more of the freezer taste when they aren't wrapped in plastic wrap first!
Can I make these M&M cookie bars in another size pan?
Yes! You don't just have to make these M&M cookie bars in a 9x13 pan. You could bake in a 9x9" pan and the bars will just be thicker. Just be sure to bake for a few extra minutes to account for the thickness.
You can also spread this in a 12" round cookie cake pan and bake for 12-14 minutes. This recipe is actually the same as my homemade cookie cake, just baked in a different pan and with M&M's!
Customize the M&M's for any holiday!
- Red & Green M&M's for Christmas Cookie Bars
- Pink & Red for Valentine's Day Cookie Bars
- Red, White, and Blue for 4th of July Cookie Bars
- Pastel M&M's for Easter Cookie Bars
I mean, you *could make* normal cookie bars but why do that when you can have chocolate chip cookie bars with M&M's?!
Chewy M&M Cookie Bars
Ingredients
Cookie Cake Recipe
- ½ cup unsalted butter You will be melting this
- ½ cup brown sugar
- ¼ cup granulated sugar
- 1 large egg
- 1 ½ teaspoon vanilla extract
- ½ teaspoon baking soda
- ¼ teaspoon baking powder
- ¼ teaspoon salt
- 1 ½ cups all-purpose flour
- ½ cup semi-sweet chocolate chips
- ½ cup M&M's
Before you begin! If you make this, will you do me a huge favor and leave a review and rating letting me know how you liked this recipe? This helps my small business thrive so I can continue providing free recipes and high-quality content for you.
Instructions
- Preheat oven to 350°F.
- In a small microwave-safe bowl, melt the butter (½ cup) for 20-30 seconds until JUST melted. You want it fully melted down without any chunks.
- Add in light brown sugar (½ cup) and granulated sugar (¼ cup) and use a spatula to stir until combined (* do not use a mixer!). Add in egg (1 large) and vanilla extract (1 ½ teaspoons), then mix. Next, add in baking soda (½ teaspoon), baking powder (¼ teaspoon), and salt (¼ teaspoon) and mix again.
- Add in all-purpose flour (1 ½ cups) and mix until all the flour disappears into the dough.
- Add the semi-sweet chocolate chips (½ cup) and M&M's (½ cup) into the dough and mix (if desired, press a few extra M&M's on top for aesthetics). Immediately proceed to pressing into pan (you don't want the dough sitting out or it will set too much with the melted butter).
- Grease a 9x13 metal pan. Drop dough into chunks then use a spatula or your hands to press down the dough into a smooth layer (being sure to get all the corners).
- Bake at 350°F for 14-15 minutes - do NOT overbake or your bars will not be soft. You want the cookie cake to be slightly brown on the top and look slightly underbaked (my oven was perfect at 14 minutes). Remove from oven and place entire pan on a cooling rack. Allow the cookie cake to cool completely before removing.
Last Step! Please leave a review and rating letting me know how you liked this recipe! This helps my small business thrive so I can continue providing free recipes and high-quality content for you.
Renee Hernandez
These bars are perfect!!! I followed the recipe step by step and it didn’t disappoint. The bars are so easy to make (I just used 1 bowl) and taste delicious. They are moist and not overly sweet. Perfect dessert to bring for my kids sports banquet. Thanks for sharing!
Melissa
So happy to hear you loved this recipe, Renee! Thank you so much for taking the time to leave a review, I really appreciate it!
Sera
Easy assembly. I had all the ingredients on hand. Took little time to bake and came out soft and delicious.
Penny H
A friend brought this to my house for a gathering. They were delicious! She sent me the recipe and I'm making them tomorrow for a meeting. My Grandkids are going to love them when I make them for a family gathering. (My 3 year old granddaughter will help me tomorrow :).
Melissa
Yay, so glad your friend shared the recipe and you enjoyed it so much! Thank you so much for taking the time to leave a review, Penny!
Jenny
Is 1.5 cups the same as 1 & 1/2 cups?
Melissa
Yes!
Theresa
These were delicious. Going to try several more of your cookie recipes. So glad I found you on Pinterest!
Jacque Keiser
My son requested an m & m ice cream cake for his adoption day celebration. Your recipe was absolutely perfect. Loved the soft cake like bars. I’ll definitely be making this again.
Melissa
That’s awesome, congratulations to you and your family! I’m glad you found this recipe to celebrate such a big day! Thanks for leaving a review, Jacque! :)
Debbie Martin
My eight year old grandson and I made these after school today. Very easy recipe for him to learn about measuring ingredients, etc. He was very excited to make them and they were very good!
Melissa
This sounds like a blast Debbie! I am so glad that you were able to have that experience together and enjoy the cookie bars!
Lynda Phillips
Great receipt loved it
Melissa
I am glad that you enjoyed the recipe Lynda, thank you for leaving a review.
Pam
These are so good! Great flavor, soft - the perfect cookie bar. I will try it in a smaller pan next time JUST to see how I feel about a thicker version but this version is so good as is.
Melissa
I'm so glad you loved them, Pam! I also have a chocolate chip bar recipe you might like to put M&M's in - it's a bit thicker & more gooey! https://www.designeatrepeat.com/chocolate-chip-cookie-bars/
Stacey
Turned out perfect. We were celebrating the last day of school. Thank you!
Melissa
Yay! So glad you guys enjoyed it!
Hal
I never thought that this could also be a possibility. OMG these look so amazing!!
Melissa
Thanks, Hal! They are dangerous little things!