Peppermint Mocha Cookie Bars

Why You’ll Love This Recipe

I enjoy this recipe because every layer offers something special: the bars are dense and chocolatey with bursts of peppermint crunch, and the frosting adds a silky, minty sweetness that ties everything together. I also love that these bars slice beautifully, making them perfect for gifting, parties, or cozy holiday evenings. They’re easy to prepare and even easier to love.

Ingredients

(Note: All ingredient amounts are listed in the recipe card below.)

White Chocolate Frosting:
1/2 cup white chocolate chips
1/3 cup heavy cream
1/8 teaspoon peppermint extract

Cookie Bars:
2 tablespoons instant espresso powder
2 tablespoons hot water
1 cup all-purpose flour
1/4 cup unsweetened cocoa powder
1/2 teaspoon salt
1/2 teaspoon baking soda
1/2 teaspoon baking powder
1/2 cup unsalted butter, softened
1/2 cup white sugar
1/4 cup firmly packed dark brown sugar
1 large egg, at room temperature
1 1/2 teaspoons vanilla extract
1/2 teaspoon peppermint extract
1/2 cup dark chocolate chips
1/4 cup finely crushed peppermint candy canes, plus more for decorating

Directions

I start by placing the white chocolate chips, heavy cream, and 1/8 teaspoon peppermint extract into a microwave-safe bowl. I microwave the mixture at 50% power in 30-second intervals, stirring between each one, until everything is smooth and combined. I refrigerate the mixture uncovered until fully chilled, about one hour.

I preheat the oven to 350°F (175°C) and line an 8×8-inch square pan with parchment paper, leaving enough overhang on all sides for easy lifting later.

In a small bowl, I stir together the espresso powder and hot water until it fully dissolves.

In a separate medium bowl, I whisk the flour, cocoa powder, salt, baking soda, and baking powder until everything is evenly combined.

In a large bowl, I beat the softened butter with the white sugar and brown sugar until light and fluffy. I add the egg and beat again. I mix in the espresso mixture, vanilla extract, and peppermint extract until fully incorporated.

I add half the flour mixture to the bowl and mix just until combined, then add the remaining flour mixture and mix again. The dough will be thick. I stir in the dark chocolate chips and crushed peppermint candy canes, then spread the dough evenly into the prepared pan.

I bake the bars for 25–30 minutes, or until the top looks just set. I let the bars cool completely in the pan for about 30 minutes.

When the frosting mixture is fully chilled, I whip it on medium-high speed with an electric mixer until it forms stiff peaks. I spread it in a thin, even layer over the cooled bars and finish with a sprinkle of extra crushed candy canes. Then I cut the slab into 16 bars.

Servings and Timing

This recipe makes 16 bars.
Prep Time: 20 minutes
Cook Time: 25 minutes
Cool Time: 30 minutes
Chill Time: 1 hour
Total Time: 2 hours 15 minutes

Variations

I sometimes add mini chocolate chips to the frosting for extra texture. When I want a stronger coffee flavor, I increase the espresso powder slightly. I also enjoy swapping some of the crushed candy canes for peppermint baking chips. For a richer chocolate base, I add a splash of hot melted chocolate to the batter before folding in the dry ingredients.

Storage/Reheating

I store the bars in an airtight container in the refrigerator for up to five days. If I want a softer texture, I let them sit at room temperature for a few minutes before eating. I avoid reheating them because the frosting softens too much. To freeze them, I wrap the un-frosted bars well, then frost after thawing.

FAQs

Can I skip the espresso?

Yes, I can leave it out, though it enhances the chocolate flavor beautifully.

Can I use peppermint baking chips instead of candy canes?

Yes, I mix them in just as I would the crushed candy.

How do I prevent the bars from drying out?

I avoid overbaking and check them at the 25-minute mark.

Can I double the recipe?

Yes, I bake a double batch in a 9×13-inch pan, adjusting baking time slightly.

Why is my frosting too soft?

It likely wasn’t chilled long enough; I chill it until very cold before whipping.

Can I melt the chocolate on the stove instead of the microwave?

Yes, I use a double boiler on low heat.

Can I use milk chocolate instead of dark chocolate chips?

Yes, though the bars will be sweeter.

Do the bars need to be refrigerated?

Yes, because of the creamy frosting.

Why didn’t my frosting whip?

It must be fully chilled; if warm, it won’t thicken.

Can I make the bars ahead of time?

Yes, I prepare them a day in advance and frost them just before serving.

Conclusion

I find these Peppermint Mocha Cookie Bars to be a delightful holiday treat that brings together chocolate, mint, and espresso in a perfectly fudgy bite. Whether I serve them at gatherings or enjoy them with a warm drink, they always add a festive touch and a burst of cozy seasonal flavor.