Peppermint-flavored icing gives this cake a seasonal flavor; the icing is poured, then spread over the top so the cake has a seamless finish. To help the cake sit level, place the bottom of an empty baking pan on top of the inverted cake as it cools, and gently push down to flatten underside.
- 1/2 cup (1 stick) unsalted butter, cut into small pieces, plus more for pan
- 1 cup all-purpose flour (spooned and leveled), plus more for pan
- 1/2 teaspoon salt
- 1/2 teaspoon baking powder
- 8 ounces semisweet chocolate, chopped
- 1 1/4 cups sugar
- 2 teaspoons vanilla extract
- 2 large eggs
- 1/2 cup low-fat buttermilk
- Chocolate-Peppermint Icing
- Whipped Cream, for serving (optional)
- Chocolate shavings or crushed peppermint candies, for serving (optional)
Preheat oven to 350 degrees. Butter and flour an 8-inch round cake pan; line bottom with parchment or waxed paper. Whisk together flour, salt, and baking powder.
In a medium saucepan, bring 2 inches water to a boil. Place butter and chocolate in a large heatproof bowl; set over (not in) water. Turn off heat; let stand until melted, 8 to 10 minutes. Stir to combine. Remove bowl; cool 5 minutes.
Whisk in sugar and vanilla, then eggs and buttermilk until combined. Fold in flour mixture until combined.
Pour batter into prepared pan. Bake until cake pulls away from sides and a toothpick inserted in center has a few moist crumbs clinging to it, 45 minutes to 1 hour. Cool in pan 5 minutes. Run a knife around edge of cake; invert onto a wire rack (and leave inverted) to cool completely, about 1 hour.
Set cake on a serving platter. Tuck parchment or waxed paper under sides of cake. Pour chocolate icing onto center of cake and spread evenly over top and sides. Let set, about 40 minutes. Serve cake with whipped cream and chocolate shavings or peppermint candies, if desired.