Guest Emmeline Duncan whips up Ground Rules Peppermint Mocha Brownies #Recipe and a #Christmas #Giveaway

Please welcome my friend, Emmeline Duncan, to the Kitchen with her delicious and festive recipe for Ground Rules Peppermint Mocha Brownies. Yum!

Like her Ground Rules Mystery series, Emmeline Duncan is based in Portland, Oregon. Her series includes Fresh Brewed Murder, Double Shot Death, Flat White Fatality, and Death Unfiltered, plus Fatal Brouhaha, which comes out in March 2025. She’s also the author of the Halloween Bookshop Mystery Series, which launched with Chaos at the Lazy Bones Bookshop in 2024 and includes Mayhem at a Halloween Wedding in 2025.

When not writing, she spends her time seeking out new coffee shops and hiking trails to explore, frequently accompanied by her Great Pyrenees. You can track her online at emmelineduncan.com

Granted, I'm biased, but one of the best recipes in the Ground Rules series is the espresso brownie recipe in Flat White Fatality. Most of my baking is dairy-free, unless I'm not planning to eat it, and then I'll use butter. You can't tell from the taste of these fudgy brownies that they’re made with oil.

To celebrate the holiday season, I've added a festive peppermint frosting.

If you're a fan of peppermint mochas, add espresso powder to the frosting. If that sounds like too much coffee flavor, leave it out, and you'll have a festive peppermint brownie.

I used a dairy-free dark chocolate chip for the frosting, but white chocolate fans could consider subbing in white chocolate chips with an optional dark chocolate drizzle. For additional holiday flare, add crushed candy canes to the top, which you can make yourself by putting a candy cane in a zip lock bag and relieving holiday frustration by pounding the candy cane with a meat tenderizer, or you can buy already crushed candy canes.

If you use dairy-free chocolate chips, these brownies will be dairy-free but not vegan. You can sub butter in for oil if desired. One added bonus of baking with oil is that baked goods tend to stay moist longer. I prefer canola oil when baking because the flavor is very neutral.

Ground Rules Peppermint Mocha Brownies

 

 

Brownie Ingredients

· 1 cup chocolate chips

· 8 tablespoons canola oil

· 3 tablespoons cocoa

· 1 teaspoon of espresso powder

· 1¼ cups sugar

· ½ teaspoon salt

· 1 teaspoon vanilla extract

· 3 eggs

· 1 cup all-purpose flour

 

Peppermint Frosting Ingredients

· 1 cup chocolate chips

· 2 teaspoons oil (coconut, canola, etc—butter or vegan butter work as well), or more if needed

· 1 teaspoon espresso powder (optional!)

· ¼ teaspoon peppermint extract

· ½ teaspoon vanilla extract

· Crushed candy canes (optional)

 

Preparation

First, bake the brownies.

Preheat the oven to 350°F (or, if you use a Breville smart oven like me, 325°F. But when I make this in my regular oven, 350 works best). Line an 8"-by 8" pan with parchment paper.

Mix the chocolate chips and canola oil in the top of a double boiler. Melt over medium-low heat, stirring regularly.

Once the chocolate has melted, remove it from heat and whisk in the cocoa powder and espresso powder. Put aside.

Whisk together the eggs, sugar, salt, and vanilla. Once it's combined, whisk in the chocolate mixture. Once it's mixed, add the cup of flour, taking care to incorporate the flour without over-whisking the mixture.

Pour the batter into the prepared pan and bake for 35–40 minutes. Keep an eye on the baking time since some ovens might bake this faster. When a toothpick comes out mostly clean, your brownies are ready.

Let the brownies cool for about an hour before removing them from the pan.

Once the brownies are cool, make the peppermint frosting by melting the chocolate chips in the top of the double boiler with the oil (or butter/vegan butter) you've chosen. If it's too dry, add a splash of more oil. You want the chocolate to be spreadable but not too liquid. You can always toss a few more chocolate chips in to thicken the frosting while melting it if needed.

Once the chocolate chips are melted, stir in the peppermint, espresso powder, and vanilla extract.

Spread the frosting on the brownies, and top with crushed candy canes (if using).

Cut into squares, and enjoy with a cup of coffee or tea. Store any leftovers in an airtight container and consume them within a day or two.

Emmeline is giving away a copy of a Ground Rules Mystery or a Halloween Bookshop Mystery of choice to a lucky winner, so leave her a lovely comment below.

As the owner of Portland, Oregon’s popular Ground Rules coffee cart, hard-working young master barista Sage Caplin is excited to expand her business with a brick-and mortar store. But not everyone gives her a warm welcome . . .

Ground Rules isn’t the only newcomer set to open in Portland’s grand new Button Building. Fortunately, most of the fellow micro-restaurant owners and patrons are great—with two exceptions. There’s Rose, a true-crime podcaster and active TikToker who’s pestering Sage for an interview about her estranged con-artist mother; and Bianca, the familiar and perpetually unpleasant owner of Breakfast Bandits. Bianca is abrasive to everyone, so Sage doesn’t feel singled out. . . . Until Bianca falls dead at the building’s grand opening—a to-go cup of Ground Rules coffee in her hand. Laced with Ketamine, also known as Special K.

It doesn’t help that just before she collapsed, Bianca was publicly rude to Sage. Or that Bianca’s boyfriend points the police toward Sage. Or that Rose, still hung up on investigating Sage’s mom, has declared she’ll solve the murder. Now it will be up to Sage to sift through a complex blend of motives, blackmail, and old and new rivalries to get to the truth of a very bitter brew . . .