Loaded M&M Oreo Cookie Bars

Loaded M&M’s Oreo Bars — Stuffed to the max with M&M’s and Oreos! These Oreo cookie bars are an easy, no-mixer recipe that’s ready in 30 minutes. Always a hit at parties!

The Best Oreo Cookie Bars

If you like Oreos and M&M’s, these are the bars for you. Is there anyone who doesn’t like Oreos and M&M’s? I hope not. Or you may be reading the wrong blog.

These bars came to be because I was preparing to move and in an effort to clean out my pantry, I started grabbing things that looked like they’d work together.

Half-eaten package of Oreos. Check. A small bag of M&M’s that appear to have most of the reds and browns picked out. Check. A stick of butter, 1 egg, 1 cup of brown sugar, and 1 cup flour. Check. I always have those items on hand.

And if you do, you can make these Oreo bars in 5 minutes without a mixer and they’re ready in a half hour. Love pans of bars for that reason. Fast, easy, no dough to chill.

I used my easy, no-mixer, go-to blondie recipe that has served me so well over the years, and I adapted it this time by stirring in chopped Oreos and sprinkling on M&M’s. It’ll seem like there are more Oreos than batter, and that’s correct. Such a such a good problem to have.

I used Birthday Cake Oreos, which have birthday cake flavored-filling, but don’t go out of your way for them. They hardly seem different from original Oreos to me.

The Oreo bars are dense, thick, and packed with texture. The Oreos soften slightly while baking, but retain some crunch.

The crunchy shells of the M&M’s, contrasted with Oreos, and the soft, buttery, moist blondie dough is a texture lover’s dream. Shopping in my own pantry and widdling down my ingredients before moving was a packer’s dream.

And my family was pretty happy when they had a taste of my pantry clean-out endeavors. They’re tailor-made for your trashy eating enjoyment. Live a little, it’s fun!

What’s in These Oreo Bars?

To make these Oreo and M&M’s cookie bars, you’ll need:

  • Unsalted butter
  • Egg
  • Light brown sugar
  • Vanilla extract
  • All-purpose flour
  • Oreo cookies
  • M&M’s

How to Make Oreo Cookie Bars

Melt the butter, then whisk in the egg, brown sugar, and vanilla. Add the flour and mix until just combined. Then, fold in then crushed Oreos. 

Turn the batter into a greased 8×8-inch pan. Sprinkle with M&M’s just before baking. 

Bake these Oreo bars until a toothpick inserted in the center (if you can find a bare patch to test) comes out clean, or with a few moist crumbs, but no batter.

Can I Use Different Flavors of Oreos?

Yes! Use whatever variety of Oreos you have on hand. Different flavors of Oreos will work here, as will Double Stuf. 

Can I Use Different Flavors of M&M’s? 

Yes again! Any kind of M&M’s can be used in these Oreo and M&M’s cookie bars. 

Can I Use Granulated Sugar Instead of Brown Sugar?

No, you must use light brown sugar in this recipe. Granulated sugar isn’t sticky enough, which will result in a different texture. 

Can I Double This Recipe? 

Most likely, yes. You’d need to bake the Oreo bars in a 9×13-inch baking pan. 

How to Store Oreo Cookie Bars

Store these Oreo cookie bars in an air-tight container at room temperature. They’ll last about a week. 

Can I Freeze These Oreo Bars? 

Yes, but just note that M&Ms can sometimes lose their color and bleed a bit upon freezing. 

Tips for Making Oreo Bars

If you don’t have Oreos or M&M’s, shop in your own pantry for what you do have. 

Graham crackers, 4-day old leftover chocolate chip cookies that are past their prime, leftover fun-sized candy bars from last Easter, the remains of your last impulse buy at Trader Joe’s like chocolate-covered pretzels or that tub of mini peanut butter cups you’ve been snacking on at midnight, or the nearly empty bag of white chocolate chips that you grab a handful of every time you walk past the cupboard.

You get the point. Don’t buy anything if you don’t have to. Sure, the Oreos and M&M’s are great but so are a lot of other things. Use the recipe as an opportunity to use up your odds and ends.

Edited to add: This recipe, and my name, appeared on the COVER of Taste of Home Magazine, September 2014. They used their in-house photographer rather than using mine. Facebook post about it here.

Yield: 9

Loaded M&M's Oreo Cookie Bars

Prep Time 5 minutes
Cook Time 20 minutes
Cooling Time 30 minutes
Total Time 55 minutes

Stuffed to the max with M&M's and Oreos! These Oreo bars are an easy, no-mixer recipe that's ready in 30 minutes. Always a hit at parties!


  • 1/2 cup unsalted butter (1 stick), melted
  • 1 large egg
  • 1 cup light brown sugar, packed
  • 1 tablespoon vanilla extract
  • 1 cup all-purpose flour
  • 18 Oreo Cookies, coarsely chopped*
  • about 1/2 cup M&M’s (I used plain, use your favorite flavor or other chopped candy)


    1. Preheat oven to 350F. Line an 8-by-8-inch baking pan with aluminum foil, spray with cooking spray; set aside.
    2. In a large, microwave-safe bowl melt the butter, about 1 minute on high power.
    3. Wait momentarily before adding the egg so you don’t scramble it. Add the egg, brown sugar, vanilla, and whisk until smooth.
    4. Add the flour and stir until just combined, don’t overmix.
    5. Stir in the Oreos.
    6. Turn batter out into prepared pan, smoothing the top lightly with a spatula.
    7. Evenly sprinkle the M&M's over the top, lightly pressing them down with your finger or a spatula.
    8. Bake for about 20 to 22 minutes, or until done based on add-ins used. Top should be set and edges slightly firm. A toothpick inserted in the center (if you can find a bare patch to test) should come out clean, or with a few moist crumbs, but no batter.
    9. Allow bars to cool in pan for at least 30 minutes before slicing and serving.


  • *Note: I used Oreo Chocolate Birthday Cake Sandwich Cookies; another type of chocolate sandwich cookie may substituted, or about 2 heaping cups of coarsely chopped add-ins including leftover cookies, graham crackers, chocolate-covered pretzels, etc.
  • Bars will keep airtight at room temperature for up to 1 week, or in the freezer for up to 6 months.

Nutrition Information:



Serving Size:


Amount Per Serving: Calories: 394Total Fat: 18gSaturated Fat: 9gTrans Fat: 0gUnsaturated Fat: 4gCholesterol: 49mgSodium: 112mgCarbohydrates: 56gFiber: 1gSugar: 37gProtein: 3g

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