The Chewiest M&M Cookie Bars

M&M cookie bars

I made these incredibly chewy, gooey cookie bars for my coworkers during the holidays and they turned out even better than expected! I know we’re well past Christmas and the rest of the December celebrations, but cookie bars are an always fun and customizable alternative to your classic chocolate chip cookies. I’m no baker (we should all know this by now), but even I could make these bars I found on Sweets by Elise’s website. After only 40-ish minutes of baking time, I came out with the most delicious chocolatey treats I want to make throughout the year by picking seasonally-appropriate M&Ms. I made two perfect batches of cookie bars, but after screwing up my third and final one, I learned that the most important part to follow in the recipe is ensuring that the eggs are room temperature and not cold. If you follow Elise’s directions to a T, you’ll surely end up with a sweet dessert that will please everyone!


  • Three cups all purpose flour
  • One tablespoon corn starch
  • One teaspoon baking soda
  • 1/2 teaspoon salt
  • One cup unsalted butter at room temperature
  • One cup brown sugar (I used light brown)
  • One cup sugar
  • One tablespoon vanilla extract
  • Three eggs at room temperature (extremely important that they be room temp!!!)
  • One and a half cup mini chocolate chips
  • One and a half cup M&Ms of choice


  1. Preheat oven to 325 degrees
  2. Spray 9×13 pan with nonstick spray
  3. Mix room temperature butter, brown sugar of choice, and granulated sugar in a large bowl fitted to a stand mixer
  4. Ensure mixture is combined with an airy and light texture
  5. Pour vanilla extract into mix
  6. Add eggs one by one (again, ensure eggs are room temperature first), mixing in between
  7. Gradually incorporate dry ingredients into wet mixture being sure not to overmix
  8. Pour chocolate chips and M&Ms in bowl and mix well
  9. Shift batter into 9×13 pan and spread out until evenly flattened
  10. Top with more chocolate chips and M&Ms
  11. Bake for 40 minutes or until top is golden brown and toothpick inserted into middle of batter comes out almost clean
  12. Cool bars completely before cutting into squares