These Christmas M&M cookie bars are soft and chewy with a delicious buttery, vanilla flavor. They’re quick, easy and look festive thanks to the red and green M&Ms. If you like your cookies extra thick and packed with chocolate chips – then you’ll love Christmas cookie bars!
Why You’re Going to Love these Christmas M&M Cookie Bars
I love making cookie bars because they’re so much faster than making traditional cookies. There’s no need to chill the dough and no sticky fingers because you don’t have to spend time forming the dough into balls. But most importantly, these M&M cookie bars are delicious. They’re thick, chewy, perfectly soft and packed with holiday M&Ms and chocolate chips.
Depending on how long you choose to bake these bars, they can verge on a little gooey (like a blondie) or more on the soft and chewy side like your favorite cookies.
Making Cookie Bars
Ok, so here’s the run down (with photos) to show you exactly how to make this bars.
- Start by preheating the oven to 350F (180C). You can either lightly grease the pan or line with parchment paper so that there’s an overhang around the edges.
- In a large bowl whisk together the melted butter, brown sugar and granulated sugar. I like to use melted butter in this recipe because it means you don’t have to wait for the butter to soften and makes the bars chewier. Win win. Make sure to whisk the ingredients together until you no longer see the melted butter sitting on top of the sugar or lumps of brown sugar.
- Then whisk in the eggs and vanilla extract. Make sure that you no longer see pieces of egg in the mixture.
- In a separate medium bowl, whisk together the dry ingredients on their own – flour, cornstarch, baking soda and salt. The cornstarch helps to make these cookie bars extra chewy. You could get away without whisking the dry ingredients together first – but I do recommend it because it ensures that the cornstarch and baking soda are evenly distributed in the batter.
- From there, mix the dry ingredients into the butter mixture. I typically do this by hand doing a few stirs with both a wire whisk and a rubber spatula. You could use an electric mixer.
- Then fold in the M&Ms and chocolate chips. One of the great things about making cookie bars is that you can pack them with way more M&Ms and chocolate chips than making cookies – which is always a win in my book.
- Spoon the batter into your prepared pan and smooth the top. At this point, you can dot a few extra M&Ms and chocolate chips on top of your bars if you like.
- They’ll need to bake for about 25-30 minutes or until the top looks golden. The bake time is also dependant on the texture you’re going for. For slightly gooier bars, I’d bake for about 25-27 minutes. The shorter bake time will make these a little more blondie-like in texture.
Note: This recipe was developed for making cookie bars. If you try to use this dough to make cookies, you can end up with flat cookies. If you’re looking for a cookie version, use this recipe for Christmas M&M cookies.
Freezing Cookie Bars
Cookie bars freeze beautifully. Just make sure they’re completely cooled before freezing. If you bake these in a disposable pan, you can wrap the pan tightly and freeze the entire pan. Alternatively, you can slice the cooled bars, wrap tightly and place in a freezer bag.
**Always thaw in the fridge, then let the bars sit on the counter to bring to room temperature. This helps to prevent the bars turning gummy when you thaw them.
Thick, chewy and perfectly tender – these Christmas M&M cookie bars have the perfect texture. Best of all, they’re packed with so many chocolate chips and M&Ms. They’re festive, simple, freeze perfectly and make for a super easy Christmas cookie.
And for more delicious Christmas cookie bar recipes, be sure to try:
- Sugar Cookie Bars – these are perfect if you like your sugar cookies soft and tender
- Gingerbread Cookie Bars – these are soft and chewy then topped with cream cheese frsoting
- Snickerdoodle Cookie Bars
Christmas M&M Cookie Bars
- 9x13 inch (23 x 33 cm) baking pan*
- 1 cup unsalted butter (226 grams) melted and slightly cooled
- 1 cup brown sugar (210 grams) light or dark
- ½ cup granulated sugar (100 grams)
- 2 large eggs
- 2 teaspoons vanilla extract
- 2 ½ cups all-purpose flour (313 grams)
- 2 teaspoons cornstarch
- 1 teaspoon baking soda
- ½ teaspoon salt
- ¾ cup red and green M&Ms (about 150 grams)
- ¾ cup chocolate chips (135 grams)
- Preheat the oven to 350F (180C). Line a 9x13 inch (23x33 cm) pan with aluminum foil, leaving an overhang around the edges. Alternatively, lightly grease the pan.
- In a large bowl, whisk together the melted butter and sugars until you no longer see the butter sitting on top of the sugar. You can also do this using an electric mixer.
- Then whisk the eggs and vanilla extract into the butter mixture until you no longer see pieces of eggs. Set aside.
- In a separate medium bowl, whisk together the flour, cornstarch, baking soda and salt.
- Whisk the dry ingredients into the wet ingredients. Then whisk together until smooth. I typically do a few stirs with a rubber spatula first, then whisk. You could also use an electric mixer. Stop mixing once you no longer see streaks or clumps of flour.
- Stir in the chocolate chips and M&Ms.
- Pour the batter into the prepared pan and smooth into an even layer.
- Bake in the preheated oven for about 25-30 minutes or until the top is golden.
- Cool the bars in the pan.
- When ready to slice, if you lined the pan with parchment lift the bars out of the pan using the overhang of parchment paper. Place on a cutting board and slice with a sharp knife. If you simply greased the pan, slice the bars in the pan.
- Pan Sizes: This recipe can be halved and made in an 8x8 inch (20x20 cm) pan. The bars will be thinner and the bake time will be about 20-25 minutes.
- M&Ms: If you purchase a 10 ounce bag of M&Ms you will have some leftover.
- Nutrition: Details provided are an estimate only and based on 1 bar, assuming the pan is sliced into 15 uniform pieces.
- Storage: Store in an airtight container at room temperature for up to 4 days. Baked and fully cooled bars and be wrapped tightly and placed in a freezer container/bag. Freeze for up to 2 months then thaw in the fridge.