INGREDIENTS FOR THE CAKE
2 cups all-purpose flour, spooned into measuring cup and leveled off with knife
2 cups granulated sugar
1 cup unsweetened natural cocoa powder, such as Hershey’s
1 teaspoon salt
2 teaspoons baking powder
1 teaspoon baking soda
2 large eggs, lightly beaten
½ cup vegetable oil
1 cup sour cream
1½ teaspoons vanilla extract
1 cup boiling water
FOR THE FROSTING
8 ounces semi-sweet or milk chocolate, broken into small pieces.
2½ sticks (20 tablespoons)
unsalted butter, softened but still cool
1¼ cups confectioners’ sugar
½ cup unsweetened natural cocoa powder, such as Hershey’s ⅛ teaspoon salt
¾ cup light corn syrup
1 teaspoon vanilla extract
STEP-BY-STEP INSTRUCTIONS
In the bowl of a stand mixer fitted with the paddle attachment, combine the flour, sugar, cocoa powder, salt, baking powder, and baking soda.
Mix on low speed for 30 seconds to combine.
Add eggs, oil, and sour cream.
Mix on low speed until combined.
Increase the speed to medium and beat for 2 minutes. Then, reduce the speed to low and gradually pour in the hot water (be careful to pour very slowly so it doesn’t splash). The batter will be soupy. Stop the mixer and scrape down the sides and bottom of the bowl; mix again until evenly combined.
Divide the batter evenly between the prepared cake pans.
Bake for about 35 minutes, or until a toothpick inserted into the center comes out clean.
Cool the cake layers in the pans on a rack for 10 minutes. Invert the cakes onto a wire rack, remove the pans and cool completely.
While the cakes cool, make the frosting.
Place the chocolate in a microwave-safe bowl.
Cook in the microwave in 20-second intervals, stirring in between, until it’s about three-quarters of the way melted. Stir, allowing the residual heat in the bowl to melt the remaining chocolate completely. (If necessary, place the chocolate back in microwave for a few seconds.) Set aside to cool.
In a food processor, combine the butter, confectioners’ sugar, cocoa powder and salt.
Process until smooth, about 30 seconds, scraping down the sides of the bowl as needed. Then add the corn syrup and vanilla.
Process until just combined, 5 to 10 seconds. Scrape down the sides of the bowl, then add the lukewarm melted chocolate.
Pulse until smooth and creamy, 10 to 15 seconds. Do not overmix.
When the cakes have cooled, place one cake layer on a serving plate. Using an icing spatula or butter knife, spread about 3/4 cup of the frosting over the first layer. Top with the second layer, then spread the remaining frosting over the top and sides of the cake, swirling decoratively.
