Devil's food cake is renowned for being dark, dense, and delicious. This classic cake recipe, made with dark chocolate and cocoa powder, exceeds expectations.
1. Heat oven to 325 degrees F. Coat two 9 x 2-inch round baking pans with nonstick flour-and-oil baking spray.
2. Coarsely chop chocolate. Place in a small microwave-safe bowl with oil. Microwave on HIGH power for 1 minute; stir until smooth. If needed, heat an additional 15 seconds. Let cool slightly.
3. In medium-size bowl, mix flour, cocoa powder, baking soda and salt. In large bowl, with mixer on medium speed, beat butter and sugar until fluffy, 3 minutes. Add eggs, one at a time, beating after each. Beat in melted chocolate mixture and vanilla.
4. Place sour cream in a 2-cup capacity measuring cup. Whisk in milk until smooth. On low speed, beat flour mixture into butter mixture, alternating with thinned sour cream, beginning and ending with flour; beat 1 minute. Spread into pans.
5. Bake at 325 degrees F for 35 to 40 minutes or until toothpick inserted in centers tests clean. Cool cakes in pans on wire racks 15 minutes. Turn cakes out onto racks; cool layers completely (about 2 hours).Frosting:
6. In large glass bowl, microwave chocolate chips on medium power for 30 seconds; stir. Microwave another 30 seconds until completely smooth. Let cool slightly. With mixer, blend 1-1/2 cups of the sugar with butter. Beat in sour cream, milk and then half of the chocolate until smooth. On low speed, beat in remaining sugar until blended; then beat in remaining chocolate. Continue to beat until good spreading consistency, about 1 minute.
7. Slice one of the cooled layers in half horizontally (insert toothpicks into sides of layer to use as guide). Repeat with other layer. Gently place one layer, cut-side down, on serving plate (layers will be tender). Spread top with 2/3 cup frosting. Repeat with remaining cake layers and frosting, ending with cake layer, cut-side down. Frost top and side of cake with remaining frosting. Refrigerate 1 hour, until firm.