3 c. all-purpose flour
2 c. granulated sugar
3/4 c. unsweetened cocoa powder
2 tsp. baking soda
1/4 tsp. salt
1 c. sour cream
1 c. cold water
3/4 c. vegetable oil
1 tbsp. vinegar
1 tbsp. vanilla

Preheat oven to 350°F. Grease and lightly flour baking pans. In a large bowl, sift flour, sugar, cocoa, soda and salt. In a second bowl, mix sour cream, water, oil, vinegar and vanilla. Beat into flour mixture about 2 minutes by hand. Spread evenly in baking pans.

Bake 25 to 30 minutes or until a wooden pick inserted in center is clean when removed. Let cool in pans on a wire rack 10 minutes.

To remove from pans, run a knife around the edge of layers and invert onto rack. When layers are completely cool, frost with Chocolate Buttercream Frosting.

Makes 3 (8-inch) layers.

Chocolate Buttercream Frosting:

2 c. confectioners sugar, sifted
3/4 c. (1 1/2 sticks) unsalted butter, softened to room temperature
6 oz. cocoa powder
1/2 tsp. vanilla extract
1/4 tsp. salt

In a mixing bowl with a hand mixer on low speed, beat sugar, butter, cocoa, vanilla and salt just until sugar is incorporated. On high speed, beat until fluffy. Decorate as desired.