Ingredients
1-1/2 cups cake flour1 cup sugar1 teaspoon baking soda1/2 teaspoon salt2 ounces unsweetened chocolate2 tablespoons butter1 cup buttermilk1/2 cup canola oil1 large egg, room temperature1 teaspoon vanilla extractFROSTING:1/2 cup sugar4-1/2 teaspoons cornstarch1/8 teaspoon salt1 ounce unsweetened chocolate, coarsely chopped1/2 cup hot coffee or water4-1/2 teaspoons butter1/2 teaspoon vanilla extract
Preparation
Preheat oven to 350°. In a large bowl, combine the flour, sugar, baking soda and salt; set aside. In a microwave-safe bowl, combine the chocolate and butter. Cover and microwave on high for 1 minute. Stir; cook until melted, 30 seconds longer.
In a small bowl, combine the buttermilk, oil and egg. Add to dry ingredients; beat just until combined. Add the chocolate mixture and vanilla.
Pour into a greased 8-in. square baking dish. Bake until a toothpick inserted in the center comes out clean, 30-35 minutes. Cool completely on a wire rack.
For frosting, in a saucepan, combine the sugar, cornstarch, salt and chocolate; stir in the coffee until blended. Bring to a boil over medium heat; cook and stir until mixture is thickened. Remove from the heat; stir in butter and vanilla. Spread warm frosting over cake.
