clock clock iconcutlery cutlery iconflag flag iconfolder folder iconinstagram instagram iconpinterest pinterest iconfacebook facebook iconprint print iconsquares squares iconheart heart iconheart solid heart solid icon
M&M cookie bars are soft and chewy, have crisp edges with a gooey center, and are loaded with M&M's and chocolate chips. The easiest way to bake cookies! |

M&M Cookie Bars

5 Stars 4 Stars 3 Stars 2 Stars 1 Star

5 from 2 reviews

  • Author: Sam Hu | Ahead of Thyme
  • Total Time: 40 minutes
  • Yield: 16 pieces
  • Diet: Vegetarian


M&M cookie bars are soft and chewy, have crisp edges with a gooey center, and are loaded with M&M's and chocolate chips. The easiest way to bake cookies!


  • 1/2 cup unsalted buttersoftened to room temperature
  • 1/2 cup light brown sugar, packed
  • 1/4 cup granulated sugar
  • 1 large egg
  • 1 teaspoon vanilla extract
  • 1 + 1/2 cups all-purpose flour
  • 1/2 teaspoon baking soda
  • 1/4 teaspoon salt
  • 1/2 cup chocolate chips
  • 1/2 cup M&M's


  1. Preheat oven to 325F. Spray a 8-inch square baking pan with cooking spray oil and line it with a piece of parchment paper, allowing the overhang to come off the 2 sides. Set aside.
  2. In a large mixing bowl, use a hand mixer or stand mixer cream together butter and sugars on medium speed until light and fluffy, about 2 minutes.
  3. Add egg and vanilla, and beat on low until incorporated. Add flour, baking soda, and salt and beat until just combined. Reserve 1 tablespoon each of the chocolate chips and M&M's (for the top), and fold in the rest.
  4. Spread the cookie dough onto the lined pan. Press in the remaining chocolate chips and M&M's on top.
  5. Bake for 30-35 minutes until golden brown, and the a toothpick inserted into the center comes out clean. The cookie dough may not look completely done in the middle, but they will continue to cook as they are cooling.
  6. Allow the cookies to cool completely in the pan. Then, use the parchment paper overhang to pull them out, slice, and serve.


How to store M&M cookie bars: Keep leftover cookie bars in an airtight container at room temperature for up to 4 days. You can also store the in the fridge for up to one week.

How to freeze cookie bars: These M&M chocolate chip cookie bars freeze really well. Let them cool completely first, then slice and store in an airtight container or freezer bag for up to 3 months.

Make ahead instructions: You can make the cookie dough up to 2-3 days in advance. Cover the bowl with plastic cling wrap when storing. When ready to bake, allow the dough to come to room temperature (about 20 minutes) before spreading onto the prepared baking pan.

How to freeze cookie dough: You can also freeze the cookie dough by rolling it into a ball and wrapping tightly in plastic cling wrap, and place inside a freezer bag. Freeze for up to 3 months. When ready to bake, allow the cookie dough to thaw overnight in the refrigerator, and allow it to come to room temperature before baking, according to recipe instructions.

For thinner bars: Spread the cookie dough into a lined quarter sheet baking pan or 9x13-inch pan to make thinner cookie bars. You will need to shorten the cook time though, so keep an eye on the cookies at the 15-20 minute mark.

Substitutions: If you are feeling creative, you can add in nuts, make simple chocolate chip cookie bars by omitting the M&M's, substitute the chocolate chip for white chocolate chips, and switch up the colors of M&M's based on the holiday that you are baking them for.

How to make a bigger batch: You can simply double the recipe and spread the cookie dough into a 9x13-inch baking pan.

  • Prep Time: 10 minutes
  • Cook Time: 30 minutes
  • Category: Dessert
  • Method: Bake
  • Cuisine: American