Old-Fashioned Sour Cream Fudge Birthday Cake

Old-Fashioned Sour Cream Fudge Birthday Cake

2 cups cake flour
2 teaspoons baking powder
1 teaspoon baking soda
1/4 teaspoon salt
3 ounces unsweetened chocolate, chopped
1/2 cup warm water
3/4 cup unsalted butter, room temperature
1 3/4 cups sugar
3 large eggs
1 cup sour cream

Frosting:
3/4 cups unsalted butter
4 1/2 ounces unsweetened chocolate, chopped
3 cups powdered sugar
3 tablespoons unsweetened cocoa powder
3/4 cup sour cream

Cake:  Preheat oven to 350 degrees.  Butter and flour three 8-inch cake pans.  Combine flour, baking powder, baking soda and salt in medium bowl.  Combine chocolate and warm water in heavy small saucepan.  Bring to boil, stirring constantly until melted.  Cool to lukewarm.  Using electric mixer, beat butter and sugar in large bowl until fluffy.  Add eggs 1 at a time, beating well after each addition.  Mix in sour cream, then melted chocolate, beating just until smooth.  Add dry ingredients and mix just until blended.

Divide batter among prepared pans; smooth tops.  Bake until cakes shrink away from sides of pans and tester inserted into center comes out clean, about 35 minutes.  Transfer to racks and cool in pans 15 minutes.  Turn out cakes onto racks and cool completely.

Frosting:  Melt butter and chocolate in heavy small saucepan over low heat, stirring until smooth.  Transfer to large bowl.  Whisk in 1 cup powdered sugar, cocoa powder and half of sour cream.  Whisk in 2 cups powdered sugar.  Gradually whisk in enough of remaining sour cream to form spreadable frosting.

Place 1 cake layer on platter.  Tuck waxed paper strips under cake to protect platter.  Spread 1/2 cup frosting evenly over cake.  Top with second cake layer.  Spread 1/2 cups frosting over.  Top with remaining cake layer.  Spread remaining frosting over sides and top of cake, swirling frosting decoratively.  Remove waxed paper strips.