These simple and fun peanut butter cookie bars filled with M&Ms are here to satisfy your sweet craving!

Peanut Butter M&M Cookie Bars

We spent a weekend in Vegas this month and since we had the kids with us, we made a stop at the M&M Factory. And you guys, sooo much candy came home with us. We’ve been slowly working our way through it, and it was only a matter of time before some M&Ms ended up in my baking.

I borrowed the recipe from my favorite peanut butter chocolate chip cookies, swapped the chocolate chips out for M&Ms, spread the dough into a baking pan because I was feeling lazy, and these bars were born. They couldn’t be simpler or more perfect for a quick homemade treat.

The kids of course loved them, and so did the adults!

Peanut Butter M&M Cookie Bars

Peanut Butter M&M Cookie Bars

baking tip:How parchment paper can make baking easier

For cookies, biscuits and scones: Line sheet pans with parchment paper before using. Prevent sticking without adding any extra grease and cleanup is as easy as throwing away the parchment!

For cakes: Line the bottoms of your cake pans with parchment paper and then either grease and flour, or coat with baking spray. You’ll never have a cake stick in your pan again!

For bars and breads: Line square or rectangular pans with parchment so that there’s a few inches of overhang on either side. When your baked good is ready to serve, use that overhang as a handle to lift it out of the pan. Then transfer to a cutting board and slice. No more messing up a slice trying to dig it out of the pan!

Peanut Butter M&M Cookie Bars

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Peanut Butter M&M Cookie Bars
5 from 1 review

Peanut Butter M&M Cookie Bars

Servings: 16 bars
Prep Time: 10 minutes
Cook Time: 25 minutes
Total Time: 35 minutes
These simple and fun peanut butter cookie bars filled with M&Ms are here to satisfy your sweet craving!


  • 1/2 cup unsalted butter (113 grams), softened to room temperature
  • 3/4 cup smooth or crunch peanut butter (200 grams)
  • 1 1/4 cup light or dark brown sugar (265 grams)
  • 1 teaspoon vanilla extract
  • 2 large eggs
  • 2 cups all-purpose flour (240 grams)
  • 3/4 teaspoon baking soda
  • 3/4 teaspoon coarse salt
  • 1 cup M&M candies (210 grams), I used mini


  • Preheat oven to 350 degrees F. Grease a 9-inch baking pan and line with parchment paper.
  • With an electric mixer beat the butter, peanut butter, and brown sugar until light and creamy. Add vanilla extract and eggs, mixing after each.
  • Add the flour, baking soda, and salt and mix until just combined. Add the M&Ms.
  • Spread the cookie dough into the prepared pan and bake until edges are golden brown and middle is puffed, 25-30 minutes.
  • For best results and prettiest slices, let cool completely before slicing. Once cool, use parchment paper to lift bars out of pan and transfer to a cutting board. Cut into 16 equal pieces.
Calories: 318kcal, Carbohydrates: 40g, Protein: 6g, Fat: 16g, Saturated Fat: 7g, Cholesterol: 38mg, Sodium: 238mg, Potassium: 126mg, Fiber: 1g, Sugar: 26g, Vitamin A: 236IU, Vitamin C: 1mg, Calcium: 42mg, Iron: 1mg
Cuisine: American
Course: Dessert
Author: Annalise Sandberg
Have you tried this recipe?I’d love to hear about it! Leave a rating and review below, or take a photo and tag it on Instagram @completelydelicious with #completelydelicious.