The holidays are a time for family, good cheer and a little indulgence. With its layers of tender, dark chocolate cake and rich white chocolate-peppermint buttercream, this holiday showstopper is all about indulgence. Though it does take some time to put together, there’s nothing difficult about the recipe, and you can break up the components by making the cake layers one day and then making the buttercream and assembling it the next day. You can use either candy canes or peppermint candies for the garnish – the candies can be difficult to crush by hand, so I do it in the food processor in short pulses. If you’re using candy canes, I find that it’s easier to crush them with a rolling pin while wrapped, then snip the end of the plastic with scissors and pour the pieces into a bowl.
Makes one 8-inch layer cake, serving 10 to 12
Chocolate Buttermilk Cake:
- 2 2/3 cups (347 grams) all-purpose flour
- 1 1/3 cups (128 grams) Dutch-processed cocoa powder
- 1 ½ teaspoons baking powder
- 1 teaspoon baking soda
- 1 teaspoon fine sea salt
- 2 1/4 cups (544 grams) whole buttermilk, at room temperature
- 2 teaspoons vanilla paste or extract
- 21 tablespoons (297 grams) unsalted butter, cut into tablespoons and softened
- 1 1/3 cups (266 grams) granulated sugar
- 1 cup (216 grams) firmly packed light brown sugar
- 4 large (200 grams) eggs, at room temperature
- 2/3 cup (160 grams) hot brewed coffee
White Chocolate Peppermint Buttercream:
- 4.5 ounces (127 grams) high-quality white chocolate, chopped
- 5 tablespoons (74 grams) water, divided
- 1 ¼ cups (250 grams) granulated sugar
- 6 large (180 grams) egg whites
- 38 tablespoons (545 grams) unsalted butter, softened but cool
- ¼ teaspoon peppermint extract
- 6 ounces (170 grams) candy canes or peppermint candies, crushed
- Pink food coloring
Make the cakes:
- Position a rack in the center of the oven and preheat the oven to 350˚F. Grease the bottom and sides of a three 8-inch round cake pans and line the bottom of each pan with a round of parchment paper, cut to fit. Dust the sides of the pans with flour, tapping out the excess.
- In a medium bowl, sift together the flour, cocoa powder, baking powder, baking soda and salt. Gently whisk to combine well and set aside.
- Stir together the buttermilk and vanilla and set aside.
- In the bowl of an electric mixer fitted with the paddle attachment, beat the butter at medium speed until creamy, about 30 seconds. Gradually add the granulated and light brown sugar and beat at medium-high speed, scraping down the sides of the bowl with a rubber spatula once or twice, until light and fluffy, about 4 minutes. Reduce the speed to low and add one-third of the buttermilk mixture, then add 2 tablespoons of the flour mixture and mix at medium speed until blended, scraping down the side of the bowl if necessary. Add the remaining buttermilk, then add the eggs, one at a time, mixing well after each addition and mixing until blended (if the batter looks curdled at any point as you are adding the eggs, add another tablespoon of the dry ingredients to smooth it out). Reduce the speed to low and add the remaining flour mixture in three additions, alternating it the hot coffee in two additions and mixing just until combined. Scrape the batter into the prepared pans, dividing it evenly, and smooth it into an even layer. Bake the cakes for 45 to 50 minutes, until a toothpick inserted into the center of each cake comes out clean. Place the cakes on wire racks and cool for 15 minutes.
- Invert each cake onto a wire rack and peel off the paper. Cool completely.
Make the buttercream:
- Place the white chocolate and 2 tablespoons of the water in a microwave-safe medium-size bowl. Cook on 50% power for 30 seconds. Remove the bowl and stir the chocolate well. Repeat, heating the chocolate for 20 second intervals, stirring after each interval, until almost completely melted. Remove the bowl from the oven and stir until completely melted and smooth. (You can melt the chocolate in a bowl set over a pot of barely simmering water, if you prefer.) Set aside to cool while you make the buttercream.
- Pour enough water into a large, straight-sided skillet so that it comes 1/2-inch up its sides. Bring the water to a simmer; reduce the heat to medium-low to maintain a simmer.
- In the bowl of an electric mixer, combine the sugar, egg whites, and water. Place the bowl in the skillet of water and whisk gently until the mixture is hot to the touch and registers 160˚F on an instant-read thermometer.
- Transfer the bowl to the mixer stand and, using the whisk attachment, beat at medium-high speed until the meringue is cool and forms stiff, shiny peaks, about 5 minutes.
- Reduce the speed to medium and beat in the butter, one tablespoon at a time. Beat in the peppermint extract. Beat at high speed until the buttercream is smooth, about 1 minute. Remove the bowl from the mixer stand and gently fold in the melted white chocolate.
Assemble the cake:
- Place one of the cake layers, flat side up, on a cardboard cake round or serving plate. Spread a generous layer of the buttercream over the top of the cake using a metal icing spatula, covering it completely. Top with another cake layer and frost the top with more buttercream. Top with the final cake layer. Spread a thin layer of buttercream over the top and sides of the cake, making it as even as possible (this is a crumb coat). Refrigerate the cake for about 20 minutes, to chill the buttercream.
- Set aside about ¾ cup of the buttercream for garnish. Spread the remaining buttercream over the top and sides of the cake, making the buttercream as smooth as possible.
Garnish the cake:
- Pat the crushed peppermint candies gently and evenly around the bottom 2 inches around the side of the cake.
- Add some pink food coloring to the remaining buttercream and stir until evenly colored. Put it into a pastry bag fitted with a medium star tip (such as Ateco #7). Pipe dollops around the edge of the top of the cake. Serve the cake immediately, or refrigerate. Remove the cake from the refrigerator an hour before serving, so that the buttercream can soften up.