M&M Cookie Bars

ByJaclyn Shimmel On10/12/202411/08/2024 Updated11/08/2024

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M&M cookie bars are the perfect quick and easy dessert! These soft-baked, chewy bars are packed with chocolate chips and colorful M&Ms, making them the perfect fun treat for birthday parties, holidays, or any occasion.

Sliced bar cookies with M&Ms and chocolate chips.

The best thing about bar cookies is that they skip the hassle of scooping and rolling cookie dough like you normally would for 2 dozen cookies. Plus, you only need one pan—not several cookie sheets like most cookie recipes require.

For more easy cookie bar recipes grab the recipes for my 7 Layer Bars, Peanut Butter Chocolate Chip Bars, and Sugar Cookie Bars too.

Three thick M&M cookie bars stacked on top of each other, with the top bar missing a bite.

The M&M bars are one of the best recipes for busy days when you want something sweet without the wait. Perfect for parties or a fun treat at home, these bar cookies with M&M’s will quickly become a family favorite!

Why you’ll love this recipe

Soft-baked and chewy – These bars have the perfect texture everyone craves.
Loaded with chocolate chips and M&Ms – Every bite is packed with chocolatey goodness.
Quick and easy – No chilling required, and only one pan to clean!
No scooping or rolling dough – Just press the dough into a pan, and you’re done!
Perfect for any occasion – Great for parties, holidays, or a fun treat at home.

Ingredient Notes

This section includes ingredient notes and substitution options. Get all measurements, ingredients, and instructions in the printable recipe card at the end of this post.

Ingredients for chocolate chip M&M cookie bars measured out and ready for baking.

Flour: Use all-purpose flour for the best texture.
Butter: Unsalted is preferred, but if using salted butter, reduce added salt to ½ teaspoon.
Brown Sugar: Light brown sugar gives a chewy texture. Dark brown sugar can be used for a deeper molasses flavor.
Vanilla: I always recommend using pure vanilla extract for best taste.
M&Ms: I used regular M&Ms but mini M&Ms or holiday M&Ms would be great options as well.
Chocolate Chips: Semi-sweet is standard, but feel free to substitute with milk chocolate, white chocolate, or even butterscotch chips.

How to Make M&M Cookie Bars

This section shows you how to make the recipe with step-by-step photos and instructions. For the full printable recipe, see the recipe card below.

Step 1: Whisk together the flour, baking soda, and salt. Set aside

Step 2: In a separate bowl, beat butter, brown sugar, and granulated sugar until light and fluffy. Add eggs and vanilla, and mix until combined.

Two image collage of mixing bowl with creamed butter and sugar in one image and the creamed butter and sugar with the addition of egg in the other.

Step 3: Gradually mix in the dry ingredients until just combined.

Dry ingredients being added to the wet ingredients in the mixing bowl gradually.

Step 4: Fold in 1 cup of M&Ms and the chocolate chips.

Two image collage of the cookie dough before and after M&Ms and chocolate chips are mixed in.

Step 5: Press the dough evenly into a parchment-lined 9 x 13 inch pan and top with remaining M&Ms.

Pro Tip:

The dough will be thick and sticky. It can be helpful to grease a spatula (or your fingers, no judgement here) with a bit of non-stick spray and use it to press the dough into the pan.

Chocolate chip M&M cookie dough topped with extra M&M's in 9 x 13 inch lined baking pan.

Step 6: Bake for 22-30 minutes, until golden brown and the center is just barley set. A toothpick inserted in the center should come out with a few moist crumbs. Keep in mind that the bars will continue to firm up as they cool.

Golden brown M&M cookie bars after baking in 9 x 13 pan.

Step 7: Set the pan on a wire rack and allow the bars cool completely in the pan before removing, slicing, and serving.

Note:

Don’t worry if some of the M&Ms on top crack while baking—this is completely normal and won’t affect the taste or texture of your cookie bars!

Cookie bars with M&Ms and chocolate chips sliced into squares on parchment paper.

Storage

Keep in an airtight container at room temperature for up to 4-5 days or in the freezer for up to 3 months.

Additions and variations

Mix in ½ cup of crushed pretzels for a salty-sweet combo.
Customize for various holidays with Halloween M&Ms, Christmas M&Ms, or Easter M&Ms.
Stir ¼ cup of sprinkles into the dough for a festive, fun treat.

Cookie bars with M&Ms and chocolate chips on parchment paper.

Tips for the Best M&M Bars

Don’t overmix the dough. Stop mixing once the dry ingredients are just combined for soft, chewy bars.
Let the bars cool completely before removing from the pan to avoid breaking or crumbling.
Customize with your favorite mix-ins like different M&Ms, chocolate chips, or even nuts!
Use a metal baking pan rather than a glass baking dish for even heat distribution and clean edges.
Do not over bake. The bars will be slightly underdone when they come out of the oven, but they’ll firm up as they cool.