3 cups all-purpose flour
2 cups sugar
1/2 cup unsweetened cocoa powder
2 teaspoons baking soda
1 teaspoon salt
2 cups hot water
3/4 cup vegetable oil
2 tablespoons distilled white vinegar
1 tablespoon instant coffee granules
1 tablespoon vanilla extract
Preheat over to 350 degrees with rack in the center. Spray two 8×2-inch round cake pans with nonstick spray.
Whisk together flour, sugar, cocoa, baking soda, and salt in a large mixing bowl.
Combine water, oil, vinegar, instant coffee, and vanilla in a large measuring cup. Add to dry ingredients and whisk just until combined – a few lumps are OK. Divide batter between pans, then bake until a toothpick inserted in the center comes out clean, 35-40 minutes. Cool cakes on a rack for 15 minutes, then invert them onto the rack. Leave cakes upside down to cool completely.
GLOSSY CHOCOLATE ICING
1 stick unsalted butter
1-1/2 cups sugar
1-1/4 cups unsweetened cocoa powder
Pinch of salt
1-1/4 cup heavy whipping cream
1/4 cup sour cream
1 teaspoon instant coffee granules
2 teaspoons vanilla extract
Melt butter in a large saucepan over medium heat. Stir in sugar, cocoa, and salt. Mixture will be thick and grainy. Combine heavy cream, sour cream, and instant coffee until smooth. Gradually add cream mixture to chocolate until blended and smooth. Cook until the sugar has dissolved and the mixture is smooth and hot to the touch, 6-8 minutes. Do not boil.
Off heat, add vanilla. Cool icing at room temperature until spreadable, 2-3 hours (Icing me be chilled until completely cold, then warmed gently in microwave until spreadable. Heat at high power in 20-second intervals, stirring well after each interval.)