Thick and Chewy M&M Cookie Bars

M&M Cookie Bars

As of today, I only have 10 days left of maternity leave. *cries* Where the heck did the past 11 weeks go? And when did my squishy newborn turn into a laughing, smiley almost 3-month old?

While I am so not ready to leave my baby girl, I will admit that I am ready to have some adult interaction, and to see my coworkers again. I am blessed that my coworkers are basically a second family to me, and are essentially another set of sisters to seek advice from, to laugh with, to cry with. They are seriously some of the most amazing, supportive women that I’ve ever met.

M&M Cookie Bars 011

As I said, with the exception a few male doctors and one male secretary, the rest of my coworkers are women. And when you work somewhere that is mostly women in their late 20’s and early 30’s, there is bound to be a baby boom. This summer alone, we’ve had 6 babies born within weeks of each other, with a 7th baby due in August. So last week, one of my coworkers graciously opened her home so we could have a “meet the new babies” party, as well as a play date for all the older kids. Thankfully there was an inflatable waterslide to keep the 25+ older kids entertained, while the moms passed around our newborns and talked about breastfeeding, sleep deprivation, and got up on all the work drama that we’ve missed while on maternity leave.

Of course, we couldn’t have a party without food, so I took along these M&M cookie bars, knowing they would be a hit with all the kids AND adults. As the name implies, they are thick and chewy, haha, and super easy to make. You could easily swap out the M&M’s for chocolate chips or peanut butter chips, but I love the bright colors that the M&M’s add.

Thick and Chewy M&M Cookie Bars

Prep Time: 10 minutes

Cook Time: 25 minutes

Total Time: 35 minutes

Yield: 12-18 bars


  • 2 cups + 2 tablespoons flour
  • 1/2 tsp salt
  • 1/2 tsp baking soda
  • 3/4 cup butter (1 1/2 sticks), softened
  • 1 cup brown sugar
  • 1/2 cup white sugar
  • 1 large egg
  • 1 large egg yolk
  • 2 teaspoons vanilla extract
  • 1 12oz bag mini M&M's, divided


  1. Preheat the oven to 325 degrees. Adjust the oven rack to lower-middle position. Grease a 9x13 pan, line with parchment paper so the edges hang over the side, then set aside.
  2. In a medium sized bowl, whisk together the flour, salt, and baking soda and set aside.
  3. In a large bowl, combine the softened butter and sugars until well mixed. Add the egg, egg yolk, and vanilla and mix well. Slowly add in the dry ingredients until just combined; do not overmix. Fold in 1 cup of the mini M&M's, then spread evenly into the prepared pan using a spatula. Sprinkle the remaining M&M's on top of the batter.
  4. Bake for 20-25 minutes, or until the top of the bars are a light golden brown, slightly firm to the touch, and edges start pulling away from sides of pan. Cool completely before cutting.

Source: What’s Megan Making

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  1. says

    Love the M&M cookie. Pinned this to my newly created cookie board at Pinterest.

    Can’t believe I haven’t had these in years.

    Good luck.

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