The dough is thick enough that pressing it across the pan feels more like shaping one giant cookie than pouring in a cake batter. Once it bakes, the edges turn golden while the center stays softer, with red and green candies and white chocolate in every slice. That contrast is what I want from Gooey Christmas Cookie Bars: a set edge and a middle that still feels tender.
I like this format because one pan cuts into 24 bars without scooping batch after batch of cookies. Parchment overhang makes it easy to lift the whole slab out once it’s cool, and the colorful candies do the decorating right inside the dough. Each bar has a buttery cookie base, little chocolate pockets, and a bright crunch from the candy shells.
Kitchen Note
Room-temperature eggs blend into the creamed butter more smoothly than cold ones. I set them out before I start, so the butter stays creamy instead of turning firm and lumpy when the eggs go in.
Save these Gooey Christmas Cookie Bars for a batch with golden edges, soft centers, and red and green candy in every bite.
Why Brown Sugar Alone Makes a Different Cookie Bar
These bars use both brown sugar and granulated sugar, and they don’t do exactly the same job. Packed brown sugar brings moisture and a deeper, almost caramel-like note that helps the middle stay soft. Granulated sugar balances that richness and supports the golden edges, so the bars don’t bake up with one uniform, heavy texture.
Changing the balance changes the result. Using only brown sugar would push the bars toward a softer, more compact bite; leaning on granulated sugar alone would make them less tender. Beating both sugars with softened butter until creamy helps distribute them through the dough before the flour goes in. I keep the proportions together for the contrast that makes each square taste like a cookie with a tender center, not a dense blondie or a dry sheet of cake.
What the Candy and Cookie Dough Each Bring to the Pan
- Unsalted butter — It gives the bars their rich, tender base and creams smoothly with the sugars when softened. A regular grocery-store butter works well; specialty butter isn’t needed. Stick with unsalted so the added kosher salt stays in balance.
- Eggs — Large eggs bind the dough and help it set as it bakes. Their size matters more than choosing a particular brand, so use large eggs for the intended dough consistency.
- All-purpose flour and baking soda — Flour gives the bars enough structure to lift and slice, while baking soda helps them bake up rather than stay dense. Standard all-purpose flour is right here; self-rising flour would change the leavening and salt balance.
- Red and green M&M’s — The candy shells keep their color and add a crisp bite against the soft dough. You can use another color of M&M’s in the same quantity if you want a different look; the flavor and texture stay much the same.
- White chocolate chips — They melt into creamy, sweet pockets that soften the candy’s crunch. Ordinary baking chips work just fine; there’s no need to seek out a premium brand for this batch.
- Vanilla extract — It rounds out the buttery dough without taking over the candy and white chocolate. A standard bottle of vanilla extract is all you need.
From Creamed Butter to Bars That Lift Cleanly
Prepare the Pan and Cream the Sugars
Heat the oven to 350°F and line a 9×13-inch metal baking pan with parchment, leaving overhang on two sides. Beat the softened butter with both sugars in a large bowl using a hand mixer on medium speed for about 2 minutes, until creamy. Scrape down the bowl if pockets of butter or sugar cling to the sides. The mixture should look cohesive, not like separate streaks of butter and sugar.
Build the Cookie Dough
Beat in the eggs one at a time, then mix in the vanilla extract. Add the flour, baking soda, and salt, and mix on low just until no dry streaks remain. Stop as soon as the flour disappears; continuing to beat after that can make the bars tougher. The dough should be thick enough to press into the pan rather than pour.
Fold in the Candy and Press
Fold in the M&M’s and white chocolate chips until they’re spread through the dough. Use a spatula rather than the mixer here, which keeps the candies intact and avoids streaks of color through the dough. Transfer the dough to the prepared pan and press it into an even layer, paying attention to the corners. An even thickness helps the edge and center bake at a similar pace.
Bake, Cool, and Slice
Bake for 24 to 28 minutes, until the edges are golden and set. A toothpick inserted in the center should come out with moist crumbs, not wet batter; waiting for a completely clean pick can leave the bars drier than intended. Cool the pan for at least 45 minutes, then use the parchment overhang to lift the bars out. Cut once the slab has settled and holds together.
Three Ways to Change the Color or Texture
Use M&M’s in another color
Swap the red and green candies for the same quantity of another color of M&M’s. The bars keep the same candy crunch and chocolate taste, but the cut squares suit a different occasion or color scheme.
Leave out the white chocolate
Omit the white chocolate chips and keep the M&M’s for a less sweet bar with more of a straightforward cookie-and-candy bite. You’ll lose the creamy white-chocolate pockets, but the dough still presses and bakes into bars.
Make a gluten-free batch
Replace the all-purpose flour with a cup-for-cup gluten-free baking flour blend, using the same volume. The bars may bake up a little more tender. If you’re baking for someone with celiac disease, use M&M’s and white chocolate chips labeled gluten-free as well.
Storage and Reheating
- Refrigerator: Keep the bars airtight at room temperature for up to 3 days; refrigerate for up to 1 week if you need longer storage. Chilling firms the butter and makes the bars denser.
- Freezer: Freeze cooled bars individually wrapped in an airtight container for up to 2 months. Thaw at room temperature before serving.
- Reheating: Warm one bar in the microwave for about 8 to 10 seconds if you want the chocolate soft again. Avoid a long blast; the candy and white chocolate can get hot before the center warms through.
Questions That Come Up When Baking These Cookie Bars
Gooey Christmas Cookie Bars
Ingredients
Equipment
Method
- Heat the oven to 350°F.
- Line a 9x13-inch metal baking pan with parchment paper, leaving overhang on two sides.
- In a large bowl, beat the butter, brown sugar, and granulated sugar with a hand mixer on medium speed until creamy, about 2 minutes.
- Beat in the eggs one at a time.
- Mix in the vanilla extract.
- Add the flour, baking soda, and salt, and mix on low just until no dry streaks remain.
- Fold in the M&M's and white chocolate chips.
- Press the dough evenly into the prepared pan.
- Bake for 24 to 28 minutes, until the edges are golden and set and a toothpick inserted in the center comes out with moist crumbs, not wet batter.
- Cool in the pan for at least 45 minutes.
- Lift the bars out using the parchment.
- Cut into bars.
