3 ounces unsweetened chocolate, broken into pieces
2 cups white sugar
2 eggs, separated
1 ¼ cups sour cream
1 ½ teaspoons baking soda
2 cups all-purpose flour
1 teaspoon baking powder
0.5 cup mini chocolate chips
1 tablespoon butter
2 tablespoons half-and-half, or more as needed
0.5 cup confectioners' sugar
0.25 teaspoon peppermint extract
Steps
Preheat the oven to 350 degrees F (175 degrees C). Grease and flour a fluted tube pan (such as Bundt®).
Bring water to a boil in a saucepan. Steep tea bags in the water for 5 minutes. Squeeze tea bags over the saucepan and discard. Bring tea to a boil.
Combine butter and chocolate in a large mixing bowl. Pour in the hot tea; whisk until melted. Beat in sugar and egg yolks using an electric mixer.
Mix sour cream and baking soda together in a separate bowl. Add to the batter, mixing well. Mix in flour and baking powder.
Beat egg whites in a glass or metal bowl until stiff peaks form. Fold into the batter. Pour batter into the prepared pan.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, about 40 minutes. Cool in the pan for 10 minutes, then invert onto a plate. Let cool completely, about 30 minutes.
Make glaze while the cake is cooling. Melt chocolate chips and butter together in a small saucepan over low heat. Stir in half-and-half until blended. Remove from heat; stir in confectioners' sugar and peppermint extract. Drizzle over cooled cake.