What could be more satisfying than a chewy, chocolatey cookie bar studded with colorful M&M’s? These Chocolate M&M Cookie Bars are the perfect treat for any occasion, from a casual afternoon snack to a festive dessert for gatherings. With a delightful combination of rich cocoa flavor and the crunch of M&M’s, these cookie bars are sure to become a favorite in your baking repertoire. Plus, they’re incredibly easy to make, requiring just one bowl and minimal cleanup. Let’s dive into the deliciousness that is Chocolate M&M Cookie Bars!
Why Chocolate M&M Cookie Bars is Worth Your Time

If you’ve ever craved the perfect blend of soft, chewy cookie and the fun burst of candy, then Chocolate M&M Cookie Bars are for you. They’re quick to whip up and are perfect for sharing with friends and family. These bars are versatile enough to be dressed up with different mix-ins or enjoyed as they are. Whether you’re hosting a party or just need a sweet treat to satisfy your cravings, these bars are guaranteed to impress. Plus, who can resist the vibrant colors of M&M’s? They not only taste great but also make any dessert look festive.
What Goes In
To make these delightful cookie bars, you will need the following ingredients:
- 1 cup unsalted butter, melted – This creates a rich, buttery flavor and helps achieve that chewy texture.
- 1 cup granulated sugar – Adds sweetness and helps with the structure of the bars.
- 1 cup packed light brown sugar – Provides moisture and a hint of caramel flavor.
- 1 large egg, room temperature – Binds the ingredients together for a perfect consistency.
- 1 teaspoon pure vanilla extract – Enhances the overall flavor profile.
- 1.75 cups all-purpose flour – The backbone of any cookie bar, giving it structure.
- 1 cup unsweetened cocoa powder – Adds richness and a deep chocolate flavor.
- 1 teaspoon baking soda – Helps the bars rise and achieve the right texture.
- 1 teaspoon salt – Balances the sweetness and enhances flavors.
- 1 tablespoon corn starch – Contributes to a tender texture.
- 1 cup semi-sweet chocolate chips – For that extra chocolatey goodness.
- 1 cup chocolate M&M’s – The star of the show, adding color and crunch.
Must-Have Equipment
Before you get started, make sure you have the following equipment:
- Mixing bowl – A large bowl for combining your ingredients.
- Whisk – For mixing the wet ingredients together.
- Spatula – To fold in the dry ingredients and chocolate chips.
- Baking pan (9×13 inch) – The perfect size for these cookie bars.
- Parchment paper – For easy removal of the bars from the pan.
- Oven – Preheated to ensure even baking.
Stepwise Method: Chocolate M&M Cookie Bars

Step 1: Preheat the Oven
Preheat your oven to 350°F (175°C). Line your 9×13 inch baking pan with parchment paper, leaving some overhang for easy removal later.
Step 2: Combine Wet Ingredients
In a large mixing bowl, whisk together the melted butter, granulated sugar, and brown sugar until smooth and well combined. Add in the room temperature egg and vanilla extract, whisking until fully incorporated.
Step 3: Mix Dry Ingredients
In a separate bowl, sift together the all-purpose flour, cocoa powder, baking soda, salt, and corn starch. This helps to aerate the dry ingredients and prevents clumping.
Step 4: Combine Dry and Wet Ingredients
Gradually add the dry mixture to the wet ingredients, folding gently with a spatula until just combined. Be careful not to overmix, as this can lead to tough cookie bars.
Step 5: Fold in Chocolate Chips and M&M’s
Carefully fold in the semi-sweet chocolate chips and chocolate M&M’s, ensuring they are evenly distributed throughout the batter.
Step 6: Bake
Pour the batter into the prepared baking pan, smoothing the top with your spatula. Bake in the preheated oven for about 25-30 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.
Step 7: Cool and Slice
Once baked, remove the pan from the oven and allow the cookie bars to cool in the pan for about 10 minutes. Use the parchment paper overhang to lift them out of the pan and transfer to a wire rack to cool completely. Once cool, slice into squares and serve!
Flavor-Forward Alternatives

If you want to switch things up or add some personal flair to your Chocolate M&M Cookie Bars, consider these alternatives:
- Use pumpkin puree instead of some of the butter for a seasonal twist.
- Add nuts such as walnuts or pecans for a crunchy texture.
- Incorporate different types of chocolate chips, like white chocolate or milk chocolate.
- Mix in a pinch of espresso powder to enhance the chocolate flavor.
- Try swapping some of the cocoa powder for peanut butter powder for a unique flavor combination.
Chef’s Notes
- For the best texture, ensure your butter is melted but not hot when mixing with the sugars.
- Using room temperature eggs helps to create a smoother batter.
- Don’t skip the corn starch; it really helps keep the bars soft and chewy.
- Feel free to experiment with different candies in place of the M&M’s for a fun twist!
Prep Ahead & Store
You can prepare the batter ahead of time and store it in the refrigerator for up to 24 hours before baking. Just be sure to bring it back to room temperature before baking. Once baked, these Chocolate M&M Cookie Bars can be stored in an airtight container at room temperature for up to a week. They also freeze well, so feel free to make a double batch and freeze some for later!
Common Questions
Can I use dark cocoa powder instead of regular cocoa powder?
Yes, using dark cocoa powder will give your cookie bars a deeper chocolate flavor, but keep in mind that it may alter the overall sweetness slightly.
What should I do if my cookie bars are too crumbly?
If your cookie bars are too crumbly, it may be due to overbaking or too much flour in the mixture. Ensure you measure your flour accurately and keep an eye on the baking time.
Can I make these cookie bars gluten-free?
Absolutely! You can substitute the all-purpose flour with a gluten-free baking blend. Just make sure the blend includes xanthan gum for better structure.
How do I know when my cookie bars are done baking?
When your cookie bars are done, the edges will look set, and a toothpick inserted in the center should come out with a few moist crumbs, but not wet batter.
Healthy-ish Favorites
- Pumpkin Oatmeal Chocolate Chip Cookies – A wholesome twist on classic cookies.
- Chocolate Butter Cake – Decadent yet satisfying for chocolate lovers.
- Avocado Brownies – A healthier alternative to traditional brownies.
- Chickpea Chocolate Chip Cookies – A surprising protein-packed treat.
Let’s Eat
Now that you have the inside scoop on making the best Chocolate M&M Cookie Bars, it’s time to gather your ingredients and start baking! These bars are not just a dessert; they are a celebration of flavor and fun. Whether you’re treating yourself or sharing with loved ones, you’ll find joy in every bite. With their irresistible combination of chewy texture and chocolatey goodness, Chocolate M&M Cookie Bars are sure to become a household favorite. Enjoy!
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Chocolate M&M Cookie Bars
Ingredients
Equipment
Method
- Preheat your oven to 350°F (175°C). Line your 9x13 inch baking pan with parchment paper, leaving some overhang for easy removal later.
- In a large mixing bowl, whisk together the melted butter, granulated sugar, and brown sugar until smooth and well combined. Add in the room temperature egg and vanilla extract, whisking until fully incorporated.
- In a separate bowl, sift together the all-purpose flour, cocoa powder, baking soda, salt, and corn starch. This helps to aerate the dry ingredients and prevents clumping.
- Gradually add the dry mixture to the wet ingredients, folding gently with a spatula until just combined. Be careful not to overmix, as this can lead to tough cookie bars.
- Carefully fold in the semi-sweet chocolate chips and chocolate M&M's, ensuring they are evenly distributed throughout the batter.
- Pour the batter into the prepared baking pan, smoothing the top with your spatula. Bake in the preheated oven for about 25-30 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.
- Once baked, remove the pan from the oven and allow the cookie bars to cool in the pan for about 10 minutes. Use the parchment paper overhang to lift them out of the pan and transfer to a wire rack to cool completely. Once cool, slice into squares and serve!
Notes
- Ensure your butter is melted but not hot for the best texture.
- Using room temperature eggs helps create a smoother batter.
- Don’t skip the corn starch; it keeps the bars soft and chewy.
