This recipe is my go-to holiday sweet whenever I need something festive, fast, and foolproof. I first developed these Christmas M&M cookie bars during a last-minute holiday cookie swap years ago, when I realized I had more guests than time and only a handful of pantry staples. The bars were a hit: chewy, buttery, and speckled with red, green, and white candies that made them look like they belonged in a bakery window. The texture sits comfortably between a cookie and a blondie — crisp on the edges, tender and slightly gooey in the center.

I love how this recipe captures everything I want from a holiday treat: nostalgia, bright colors, and the kind of sweetness that prompts compliments. They slice into neat bars for platters or wrap beautifully for gifting. What makes them special is the balance of buttery richness from the butter and brown sugar, the light snap from the edges, and the way the M&Ms keep their shape and add a playful crunch. These bars have become part of our family holiday traditions — my niece insists on pressing extra candies on top, a flourish that always earns smiles.

Ingredients

• Unsalted butter, softened: 1 cup. Use a high-quality butter like Plugr, Kerrygold, or whatever you prefer for baking. Softened (not melted) butter traps air when creamed with sugar to create a light but tender texture.
• Granulated sugar: 1 cup. Provides sweetness and contributes to crisp edges when combined with brown sugar.
• Brown sugar, packed: 1 cup. I recommend light brown sugar for a mild molasses note that keeps the center moist; dark brown sugar will make the flavor more caramel-forward.
• Eggs: 2 large. Eggs bind the dough and provide structure. Bring them to room temperature for easier emulsification.
• Vanilla extract: 2 teaspoons. Pure vanilla extract adds aroma and rounds out the flavors; avoid imitation vanilla if possible.
• All-purpose flour: 2 3/4 cups. Measure by spooning flour into the cup and leveling with a knife for accuracy to avoid dense bars.
• Baking soda: 1 teaspoon. Gives a gentle lift and helps the bars set with a slightly airy crumb.
• Salt: 1/2 teaspoon. Balances the sweetness and enhances the chocolate flavors.
• Chocolate chips: 1 cup. Semi-sweet chips are a classic choice; you can substitute milk or dark chocolate depending on preference.
• Holiday-colored chocolate candies: 1 to 1 1/2 cups. Use red, green, and white M&Ms or similar candies. Reserve a handful to press on top for decoration before baking.
• Optional: Extra candies to press on top before baking for a glossy, festive finish.

Instructions

Preheat and prepare: Preheat your oven to 350°F (177°C). Line a 9x13-inch baking pan with parchment paper, leaving an overhang on the sides for easy removal. Lightly grease the parchment or the pan if you prefer. Proper preheating ensures even baking and predictable browning on the edges. Cream butter and sugars: In a large bowl, use a hand mixer or stand mixer fitted with the paddle attachment to cream together the softened butter, granulated sugar, and packed brown sugar on medium speed for 2 to 3 minutes until pale and fluffy. This step traps air and creates a tender crumb. Scrape down the bowl to ensure even mixing. Add eggs and vanilla: Add the eggs one at a time, mixing well after each addition so the mixture stays emulsified. Add the vanilla extract and mix just until combined. Overmixing here can encourage gluten development later, so keep the beaters on low once the eggs are incorporated. Combine dry ingredients: In a separate bowl, whisk together the all-purpose flour, baking soda, and salt. Slowly add the dry mixture to the wet ingredients in two additions, mixing on low speed until just combined and when there are no visible streaks of flour. The batter will be thick but scoopable. Fold in chocolate and candies: Gently fold in the chocolate chips and 1 cup of the holiday candies with a rubber spatula. Save the remaining candies for pressing on top; folding too many on the surface causes them to break during mixing. Bake: Spread the dough evenly in the prepared pan using a spatula or lightly oiled hands for a smooth surface. Press the reserved candies lightly into the top for decoration. Bake at 350°F for 18 to 22 minutes, or until the edges are golden brown and the center is set but still soft when gently pressed. Avoid overbaking to keep a chewy center. Cool and slice: Allow the pan to cool on a wire rack for at least 30 minutes to set. Use the parchment overhang to lift the slab from the pan, transfer to a cutting board, and slice into squares or bars using a sharp knife. For cleaner cuts, chill for 15 minutes before slicing.

Storage Tips

Store cooled bars in an airtight container at room temperature for up to 4 days. If you live in a warm climate or it is very humid, refrigerate to prevent melting of the candy coating; bring to room temperature before serving for best texture. For longer storage, wrap individual bars tightly in plastic wrap and place them in a freezer-safe container or bag for up to 3 months. Thaw wrapped bars in the fridge overnight or on the counter for a couple of hours. Reheat briefly in a warm oven (300°F for 5 minutes) for a just-baked feel.

Ingredient Substitutions

To make these bars dairy-free, substitute a vegan baking stick or plant-based butter measured 1:1 and use dairy-free chocolate chips. For egg substitutes, use 2 tablespoons of ground flaxseed mixed with 6 tablespoons warm water (let sit 5 minutes) as a binder, though texture will be slightly denser. Swap half the all-purpose flour for whole wheat pastry flour for a nuttier flavor, but reduce the amount by 2 tablespoons if the dough feels too dry. You can also switch the chocolate chips to white chocolate or butterscotch for a festive twist.

Serving Suggestions

Serve warm with a scoop of vanilla ice cream for a comforting dessert, or plate small bars on a festive platter with dusted powdered sugar and mint sprigs for holiday gatherings. These also pair beautifully with coffee, hot chocolate, or a lightly spiced mulled wine. For a kid-friendly treat, arrange bars in holiday-themed boxes with parchment for gifting. Garnish individual servings with a single fresh candy or a sprig of rosemary for a grown-up touch.

Seasonal Adaptations

While red, green, and white candies make these perfect for Christmas, the base formula adapts easily: use pastel candies for Easter, red and pink for Valentine’s Day, or orange and black for Halloween. In winter, add 1/2 teaspoon ground cinnamon and a pinch of nutmeg for warmth; in summer, fold in chopped toasted pecans and a splash of orange zest for brightness. The technique of pressing candies on top before baking stays the same and lends a finished look for any holiday.

Meal Prep Tips

Make a double batch and freeze in portions for easy dessert stocking: slice bars, separate layers with parchment, and freeze flat in a container. Pull out the quantity you need and thaw at room temperature. For grab-and-go breakfasts or snack boxes, pair one bar with Greek yogurt and fresh fruit for balance. If you prep ahead, wait to press the final candies on top until just before baking to keep them vibrant.

Success Stories

Readers have told me they turn these into an annual tradition: one friend said she bakes three pans and gives them as neighbor gifts, another uses the bars as a bake sale mainstay that sells out quickly. For our family office party, I made mini versions in an 8x8 pan and they disappeared within an hour. The most memorable feedback was from a picky teenager who announced these bars were the only holiday treat worth eating — a compliment every baker cherishes.

These Christmas M&M cookie bars are dependable, festive, and endlessly adaptable. Whether you’re baking for a crowd, gifting to friends, or simply satisfying a seasonal sweet tooth, they deliver bright color, comforting texture, and simple joy. I hope they become as much a holiday staple in your home as they are in mine.