If you’re looking for an easy dessert that feeds a crowd, these M&M Cookie Bars baked in a sheet pan are the perfect solution! They come together quickly with simple ingredients and deliver that classic chewy cookie texture in every bite. Plus, baking cookies in a sheet pan makes prep and cleanup a breeze—no scooping or chilling required! These cookie bars are a family favorite in our home, and I know they’ll be a hit in yours too. After all, M&Ms and cookies together? That’s dessert perfection! Whether you’re making them for a party, potluck, or just a fun weekend treat, this easy cookie bar recipe is one you’ll come back to again and again.
These are so good year round. At Christmas be sure and use the mini Christmas colored candies!
Need another sheet pan dessert to feed a crowd? Try my Sheet Pan Rice Krispie Treats!
Ingredients
- butter
- brown sugar
- granulated sugar
- eggs
- milk
- vanilla
- flour
- cornstarch
- baking soda
- baking powder
- salt
- chocolate chips
- mini M&Ms
See exact quantities in recipe card below
Instructions
First, preheat your oven to 325°F and generously spray a standard half sheet pan (13x18) with nonstick spray; set it aside. In a large mixing bowl, combine the butter and sugars and mix on medium speed until smooth and creamy. Next, add in the eggs, milk, and vanilla extract, mixing until fully incorporated. Then, add the dry ingredients and mix just until mostly combined. Gently fold in the chocolate chips, being careful not to overmix.
Now, turn the dough out onto your prepared baking sheet and begin spreading it evenly—take your time, it will all fit! A helpful tip: spray your fingers with cooking spray to make pressing the dough into the pan easier and less sticky. Once smooth, sprinkle mini M&Ms over the top and gently press them in using a spreader or butter knife.
Bake for 22 minutes, then begin checking for doneness. You may need up to 25 minutes, but it’s best to slightly underbake them, as the bars will continue to cook a bit in the pan after being removed from the oven. They may appear puffy at first—if so, you can gently tap the pan on the counter to help them settle. Finally, sprinkle the remaining chocolate chips and M&Ms on top, let them cool completely, and then slice into bars.
See it in action HERE!
Equipment
A well stocked kitchen makes baking so much more fun! A good quality sheet pan is essential for this recipe and so many more recipes. Here is an affiliate link to my FAVS!
Storage
If you don't have a sheet pan cover...be sure and order one NOW! These will keep for about 3 days on your counter if they even last that long!
These are honestly the best cookie bars you will make! I love making them for parties, get togethers, athletic teams, church events ETC!
Top Tip
You are going to think you don't have enough batter, but you DO! Just keep pressing!
More Sheet Pan Recipes
Christmas Idea
I love to make these for Christmas too!
Quick Weeknight Meals
M&M Chocolate Chip Cookie Bars
Equipment
Ingredients
- 1 cup unsalted butter very soft, almost melted
- 1 cup granulated sugar
- 1 ½ cups brown sugar packed
- 2 Tbsp. milk whole is best
- 3 large eggs room temperature
- 1 Tbsp. pure vanilla extract
- 3 ½ cups all purpose flour
- 2 teaspoon cornstarch
- 1 teaspoon baking soda
- 1 teaspoon baking powder
- 1 teaspoon salt
- 1 ½ cups chocolate chips (I use semi sweet but use your favorite
- ½ cup mini M&Ms
- ¼ cup chocolate chips to sprinkle on top after baking - I use Minis
- ¼ cup mini M&Ms
Instructions
- Preheat the oven to 325°F. Spray a standard half sheet pan with nonstick spray (size is 13x18) and set aside. Add the butter and sugars together in a mixing bowl and mix on medium speed until smooth. Add the milk, eggs and vanilla. And mix until combined. Add the dry ingredients. Mix until mostly combined. Add the chocolate chips in and fold just until combined. Add the batter to the prepared baking sheet. Spread evenly until smooth. All of the batter will fit perfectly, it just takes smoothing. I like to use a cake spreader. I also like to spray my finger with cooking spray and press that way. Add the mini M&Ms on top and smooth in with a spreader or butter knife.
- Bake for 27-37 minutes. I start checking at 27 minutes. You will want to lightly underbake because these cook in the pan a tiny bit after removing from oven. The cookie pan should be golden, but not brown. They will be a little puffy at first but will settle. Tapping them gently on the counter will help them to settle. Sprinkle the remaining chips and m&ms on top. Cool completely and cut.
Madhu says
These M&M Cookie Bars sound incredible! No chilling or scooping makes this the perfect easy recipe for feeding a crowd.
Misty Tannery says
Yes, it is for sure so so easy!
Ray says
Time was incorrect. cake was completely raw. took more than 23-25 minutes. also had to adjust the temperature to cook the middle because the outside was already browned
Misty Tannery says
Hi Ray!
I tried to email you. I am so sorry that your sheet pan cookie didn't turn out. I am wondering if you used a 13x18 sheet pan. Mine usually takes about 25 minutes. But if I have it in a smaller pan...say a 9x13 it takes way longer. Every now and then it takes a few minutes longer. I will adjust the recipe card to make sure I am clear on the time, thank you. I just like to start checking at 22 minutes because every oven is different. When baking sheet pan cookies you can not test the center because they will be gooey. But as soon as they are slightly golden on top and if you shake the pan gently and there is no jelly like movement in the center it is done. Again, I am sorry yours didn't work. My edges usually get done first but just a few minutes later that entire cookie is a soft golden color and I am able to keep it at 325. I hope you will try it again and I do apologize that happened.