Name: M&M Cookie Bars Recipe
Prep time: 10 min
Cook time: 30 min
Total time: 40 min
Cuisine: American
Ingredients: 3 cups all-purpose flour; 3/4 teaspoon baking soda; 3/4 teaspoon salt; 2 sticks unsalted butter (at room temperature); 1 cup granulated sugar; 1 cup golden brown sugar (firmly packed); 3 large eggs; 1 1/2 teaspoons pure vanilla extract; 1 1/2 cups M&M’s (plus more for topping); 1 cup mini chocolate chips (plus more for topping)

Jump to Recipe· 4.1 from 8 reviews

I absolutely love treating myself to a batch of these colorful, chewy delights that never fail to brighten my day. This M&M Cookie Bars Recipe is my go-to comfort dessert when I want something sweet, easy, and irresistibly fun. The combination of rich, buttery dough with bursts of candy-coated M&Ms and melty chocolate chips makes every bite a celebration.

Why You’ll Love This M&M Cookie Bars Recipe

What really makes this M&M Cookie Bars Recipe stand out to me is its perfect balance of flavors and textures. The cookie dough is soft and buttery without being overly sweet, and the M&Ms add just the right pop of color and crunch that takes it to another level. Every bite feels like a little party in my mouth, and honestly, it’s hard to stop at just one bar!

I also appreciate how straightforward this recipe is. I’m not one to spend forever fussing in the kitchen, and with just a handful of everyday ingredients, I’m able to have a batch of bars ready in under an hour. These bars are perfect for virtually any occasion, whether it’s a casual family dessert, a festive holiday cookie platter, or just a treat to enjoy while binge-watching my favorite shows. Plus, I love that the bars are easy to slice and share, which makes them an absolute winner in my book.

Ingredients You’ll Need

The image shows nine bowls and a pair of sticks of butter arranged on a white marbled surface. There are three brown eggs in a small white bowl in the top left, next to a large white bowl filled with white flour on the top right. Below the eggs, three sticks of butter are stacked side by side. In front of the butter, a medium wooden bowl is filled with small dark brown chocolate chips. To the right of this, a medium wooden bowl holds white sugar. A larger wooden bowl at the bottom right contains packed brown sugar. In the bottom middle, a white round cup is filled to the top with colorful M&M candies, showing red, blue, green, yellow, orange, and brown colors. Small wooden bowls on the bottom left hold salt, vanilla extract, and baking soda, placed close together. Photo taken with an iphone --ar 4:5 --v 7

The beauty of this recipe lies in its simple but essential ingredients that each play an important role in flavor, texture, and appearance. From the creamy butter to the colorful M&Ms, every item contributes to making these cookie bars absolutely irresistible.

Unsalted butter (2 sticks, room temperature): Provides a rich, creamy base that keeps the bars tender and moist.
Granulated sugar (1 cup): Adds sweetness and helps create a soft crumb texture.
Golden brown sugar (1 cup, firmly packed): Delivers a deeper, caramel-like flavor and chewy bite.
Large eggs (3): Bind everything together and add moisture.
Pure vanilla extract (1 1/2 teaspoons): Enhances the overall flavor with a warm, sweet aroma.
All-purpose flour (3 cups): Gives structure to the bars, helping them hold their shape.
Baking soda (3/4 teaspoon): Helps the bars rise just enough to stay soft yet set.
Salt (3/4 teaspoon): Balances the sweetness and intensifies flavors.
M&M’s (1 1/2 cups, plus more for topping): Adds colorful crunch and a playful touch to every bite.
Mini chocolate chips (1 cup, plus more for topping): Melts slightly to create pockets of gooey chocolate throughout.

Directions

Step 1: First, I preheat my oven to 350 degrees Fahrenheit to get it ready for baking. This ensures consistent heat when the bars go in.

Step 2: Then, I line a 9×13-inch baking dish with foil, making sure to leave some overhang on the edges. This foil trick is my favorite because it makes it so easy to lift out the bars when they’re done without any mess.

Step 3: Before adding the dough, I spray the foil generously with nonstick cooking spray so the cookie bars don’t stick and come out perfectly smooth on the bottom.

Step 4: In the bowl of my stand mixer, I beat the room temperature butter, granulated sugar, and golden brown sugar together until the mixture becomes light and fluffy. This step is crucial as it creates a tender, airy base.

Step 5: Next, I add in the eggs one at a time, along with the vanilla extract, beating after each addition. This helps incorporate air and flavor evenly.

Step 6: I then lower the mixer speed and gradually add the all-purpose flour, baking soda, and salt. I mix just until everything is combined to keep the bars tender without overworking the dough.

Step 7: Folding in the M&M’s and mini chocolate chips is one of my favorite parts. I reserve some to sprinkle on top later for extra crunch and a pretty finish.

Step 8: I transfer the cookie dough to my prepared baking dish, spreading it out evenly with a spatula or my hands to fill the pan neatly.

Step 9: To make the bars extra colorful and chocolatey, I press the reserved M&M’s and mini chocolate chips into the top of the dough, creating a fun, inviting surface.

Step 10: Then, I bake the bars for 30 to 35 minutes until they’re just set and turn a light golden brown. The centers should be firm but still soft.

Step 11: Finally, I let the bars cool completely in the pan before lifting them out with the foil overhang and cutting them into 18 squares. Cooling fully helps them hold together perfectly when slicing.

Servings and Timing

This M&M Cookie Bars Recipe makes about 18 servings, making it excellent for sharing with friends or enjoying over several days. The prep time is around 10 minutes, while baking takes about 30 to 35 minutes. Including cooling, you’re looking at a total time of approximately 45 to 50 minutes, ideal for whipping up a quick dessert without needing to plan too far ahead.

How to Serve This M&M Cookie Bars Recipe

A close-up of a single square bar held by a woman's hand shows a thick, soft cookie base in light golden brown with a slightly crumbly texture. The top layer is decorated with colorful candy-coated chocolates in bright blue, red, green, and yellow, each with a clear white 'm' printed on them. Scattered around the candies are small, dark chocolate chips, some slightly melted into the cookie surface. The background is a white marbled texture, emphasizing the vibrant colors and details of the cookie bar. Photo taken with an iphone --ar 4:5 --v 7

I think these cookie bars are wonderful served at room temperature, so the flavors really shine and the texture is perfectly chewy. For an extra indulgent treat, I sometimes warm individual bars for 10-15 seconds in the microwave—this brings the mini chocolate chips to molten perfection without losing their shape.

For entertaining, I love arranging the bars on a festive platter garnished with a sprinkle of extra M&Ms around the edge. They look so inviting and colorful! They pair beautifully with a cold glass of milk or a scoop of vanilla ice cream, especially during warmer months. If you want to be playful, a cup of hot cocoa or coffee is a cozy companion in cooler weather.

These bars are ideal for family dinners, holiday cookie exchanges, birthday parties, or casual get-togethers. I usually cut them into modest squares so everyone can sample a few without feeling overwhelmed—plus it’s easier to share the joy!

Variations

I love customizing this recipe to keep it fresh and exciting. For example, swapping the all-purpose flour with a gluten-free blend works wonderfully for my gluten-sensitive friends without sacrificing chewiness. Vegan bakers can try replacing butter with coconut oil and eggs with flax eggs—though this changes the texture slightly, it still results in tasty bars.

If you aren’t a huge fan of M&Ms, swapping them out for your favorite candy mix-ins like Reese’s Pieces or chopped peanut butter cups is a total game-changer. For added chewiness, I sometimes add a handful of chopped walnuts or pecans, which gives a nice nutty crunch.

For a different twist, I’ve even baked this dough as individual cookies or shaped it into bite-sized balls for no-bake treats, though the bars remain my absolute favorite form. Feel free to experiment with baking times and mix-ins to make this recipe your own!

Storage and Reheating

Storing Leftovers

I store leftover M&M cookie bars in an airtight container at room temperature for up to five days. Using a container that fits snugly helps maintain their moisture and chewiness. If you don’t plan to eat them quickly, storing the bars in the fridge also works well, though I prefer to bring them back to room temperature before serving for optimal softness.

Freezing

These cookie bars freeze beautifully, which is great for making ahead or saving extras. I wrap the cooled bars tightly in plastic wrap, then aluminum foil, or alternatively place them in freezer-safe zip-top bags with as much air removed as possible. Frozen cookie bars keep well for up to three months. When ready to enjoy, I let them thaw at room temperature or warm them in the oven briefly.

Reheating

The best way to reheat is gently warming the bars in a preheated oven at 300 degrees Fahrenheit for about 5 to 7 minutes. This method revives the soft, gooey texture without drying them out. I avoid microwaving large batches because it sometimes makes them too soft or chewy unevenly, but quick 15-second bursts work for single servings nicely.

FAQs

Can I use regular-sized M&Ms instead of mini ones?

Absolutely! If you only have regular-sized M&Ms on hand, they work just fine. The bigger candies will make the bars chunkier and provide a slightly different texture, but they will still be delicious.

What can I use to substitute eggs in this recipe?

For egg substitutes, flax eggs are a popular choice—mix 1 tablespoon of ground flaxseed with 3 tablespoons of water per egg and let it gel before adding. Applesauce or mashed banana can also work but will add a bit of their own flavor.

How do I know when the bars are done baking?

You’ll want to look for a light golden brown color on top, and the edges will be slightly firmer. The center should be set but might still look soft—this is key to keeping them chewy instead of dry.

Can I double this recipe for a larger batch?

Yes, doubling works if you have a larger baking dish or want to bake the bars in two batches. Just make sure to adjust baking times slightly depending on the depth of the dough and keep an eye on them to avoid over-baking.

Are these bars good for freezing and making ahead?

Definitely! They freeze very well, making them a perfect make-ahead treat. Just freeze after cutting and thaw or warm as needed; they’ll taste freshly baked with minimal effort.

Conclusion

I hope you feel as excited as I do to try this M&M Cookie Bars Recipe. It’s truly one of my favorite ways to satisfy a sweet tooth with minimal fuss and maximum joy. Whether you’re sharing them with loved ones or sneaking a few for yourself, I promise these cookie bars will become a beloved staple in your dessert rotation.