Peppermint Brownie Bars: Easy, Irresistible Hot Chocolate Treats for Christmas Parties

Peppermint brownie bars bring the flavors of a mug of peppermint hot chocolate to a dessert you can cut and share. A fudgy cocoa base holds a soft marshmallow topping, a drizzle of chocolate, and crushed candy canes. They’re well suited to Christmas parties because one small pan makes 16 rich squares, and most of the work can be done before guests arrive.

The brownie batter comes together in a bowl without a mixer. The marshmallows go on near the end of baking, just long enough to soften and stick together. For the neatest bars, leave plenty of time for cooling and add the candy cane pieces close to serving.

Peppermint brownie bars with marshmallow topping

These hot chocolate brownies use unsweetened cocoa powder rather than hot cocoa mix. Cocoa gives the batter its chocolate flavor without adding the sugar, milk powder, or other ingredients found in drink mixes.

– Yield: 16 bars
– Prep time: About 20 minutes
– Baking time: 27–33 minutes
– Cooling and setting time: About 90 minutes
– Total time: About 2 hours 25 minutes
– Equipment: 8-inch square metal baking pan, parchment paper, mixing bowl, whisk, spatula, and a small microwave-safe bowl

Ingredients

For the cocoa brownie base:

– ½ cup (113 g) unsalted butter, plus a little for greasing the pan
– 1 cup (200 g) granulated sugar
– ½ cup (about 42 g) unsweetened natural cocoa powder
– ¼ teaspoon fine salt
– 1 teaspoon vanilla extract
– ¼ teaspoon peppermint extract, optional
– 2 large eggs
– ½ cup (65 g) all-purpose flour

For the topping:

– 2 cups (about 90 g) mini marshmallows
– 2 ounces (57 g) semisweet chocolate, finely chopped
– ¼ cup (about 30 g) crushed candy canes or peppermint hard candies

Use peppermint extract rather than mint extract if you want a candy cane flavor. Mint extracts may contain spearmint, which gives a different taste. The extract is optional because the crushed candy already supplies peppermint flavor.

Instructions

1. Prepare the oven and pan. Heat the oven to 350°F (175°C), with a rack in the center. Lightly grease an 8-inch square metal baking pan. Line it with parchment paper, leaving an overhang on two opposite sides so you can lift out the cooled brownies.

2. Mix the butter, sugar, and cocoa. Melt the butter in a microwave-safe bowl or a small saucepan. Transfer it to a mixing bowl if needed, then whisk in the sugar, cocoa powder, and salt. The mixture will look thick and somewhat grainy. Let it cool until warm rather than hot.

3. Add the flavorings and eggs. Whisk in the vanilla and optional peppermint extract. Add the eggs one at a time, whisking until the batter looks smooth and glossy.

4. Fold in the flour. Add the flour and stir with a spatula just until no dry streaks remain. Scrape the bottom and sides of the bowl, then spread the thick batter evenly in the prepared pan.

5. Bake the brownie base. Bake for 25–30 minutes. The edges should be set, and a toothpick inserted into the center should come out with moist crumbs rather than liquid batter. Begin checking at the earlier time, since ovens and pans vary.

6. Soften the marshmallows. Scatter the mini marshmallows evenly over the hot brownies. Return the pan to the oven for 2–3 minutes, until the marshmallows puff and begin to join together. They do not need to brown. Set the pan on a wire rack.

7. Add the chocolate drizzle. Melt the chopped chocolate in a microwave-safe bowl in 15- to 20-second intervals, stirring between each interval. Stop heating when a few small pieces remain, then stir until smooth. Drizzle it over the marshmallows.

8. Cool before cutting. Let the brownies cool completely and allow the chocolate to set, about 90 minutes in a cool kitchen. If necessary, refrigerate the cooled pan briefly to firm the chocolate.

9. Finish and portion. Add the crushed candy canes close to serving. Lift the brownies from the pan using the parchment. Cut into 16 squares with a sharp knife, wiping the blade between cuts. A very light coating of neutral oil on the knife can help with the sticky marshmallow layer.

Getting a fudgy base and a soft marshmallow topping

A small amount of flour gives this cocoa brownie recipe enough structure to support the topping while keeping the center dense. Measure the flour lightly: spoon it into the measuring cup and level it, or use a scale. Scooping directly from the bag can pack in more flour and produce a drier brownie.

Don’t wait for the toothpick to come out completely clean. Brownies continue to firm as they cool, and the pan returns to the oven after the marshmallows are added. Wet batter needs more baking, but a few damp crumbs are a useful sign that the center is ready.

The marshmallow brownie topping needs only a short time in the oven. Prolonged baking can make the marshmallows chewy as they cool. Broiling is unnecessary and can scorch both the topping and exposed parchment.

Let the bars cool in the pan rather than trying to lift them out warm. The brownie base is delicate before it sets, and warm marshmallow tends to pull when cut.

Making the bars ahead for a Christmas party

These holiday party brownies are easiest to prepare earlier in the day or the evening before. Bake them, add the marshmallows and chocolate, and let everything cool completely. Cover the pan without pressing the cover against the topping.

Save the crushed candy canes for shortly before serving. Peppermint candy absorbs moisture from the marshmallows and the surrounding air, so the pieces can soften, become sticky, and bleed red streaks during storage. Adding them late preserves more crunch and keeps the colors distinct.

For a dessert tray, place each square in a small paper baking cup. The cups make the sticky bars easier to pick up and keep them from clinging to neighboring cookies. If you’re transporting them, arrange the squares in a single layer in a rigid, covered container.

Serve them at room temperature. The base will be softer than it is straight from the refrigerator, and the peppermint flavor will be easier to taste.

Storage and practical substitutions

Store the finished peppermint dessert bars in an airtight container at cool room temperature for up to 3 days. Keep them away from direct sunlight and heat, which can soften the chocolate drizzle. In a warm kitchen, refrigerate them and let individual portions stand at room temperature briefly before serving.

For longer advance preparation, freeze the plain, fully cooled brownie base without toppings for up to 2 months, wrapped tightly and placed in a freezer-safe container. Thaw it while wrapped, then unwrap, return it to the pan, and warm it in the oven before adding the marshmallows. Watch closely and remove it once the marshmallows have softened.

Bittersweet chocolate can replace semisweet chocolate in the drizzle if you prefer a less sweet finish. Crushed peppermint hard candies work in place of candy canes. Avoid adding extra peppermint extract casually; its strength varies by brand, and too much can overwhelm the cocoa.

For a holiday spread with several desserts, cut the pan into 25 small pieces instead of 16. The marshmallow, chocolate, and peppermint make even a small square a satisfying accompaniment to coffee or a modest cup of hot chocolate.