Sour!

With the crap weather that we (in the northeast) experienced over Memorial Day weekend, my activities were limited–shopping, movie watching, baking, cocktail making... And because my assistant bakers have grown tired of making regular old cookies (BOOORRRRING!), we invested our time and energy into a multi-layer cake recipe (after a lengthy process of elimination) that even called for cake flour, a very fine, low-protein flour that yields a more tender cake crumb. (Ignore the larger holes pictured–that is more likely the result of snacking than actual cake texture.) (Also please ignore my photo quality. Forgot my real camera yet again!) Personally I questioned the potential success of a frosting made entirely of chocolate and sour cream, but I kept those doubts to myself. I totally expected it to break and to be generally disgusting, but when you think about it, it's not unlike making a ganache. And the addition of the white chocolate chips was our improvisational approach to cake decorating. The results? Perfection. Nearly. The assistant bakers' mom has requested it as her annual birthday cake and another weekend guest immediately asked for the recipe. Success!

Golden Cake with Chocolate Sour Cream Frosting
Adapted from Gourmet

3 1/2 cups cake flour (not self-rising)
1 tablespoon baking powder
3/4 teaspoon baking soda
1 teaspoon salt
2 sticks (1 cup) unsalted butter, softened
2 cups sugar
4 large eggs at room temperature
2 teaspoons vanilla
2 cups sour cream

Frosting
1 1/4 pounds fine-quality milk chocolate, finely chopped
10 ounces fine-quality semisweet chocolate, finely chopped
3 cups sour cream
2 teaspoons vanilla

1. For the cakes: Preheat the oven to 350°F. Butter 2 (9- x 2-inch) round cake pans and line the bottoms of each with rounds of wax or parchment paper. Butter paper and dust pans with flour, knocking out excess. (Also works eliminating parchment, and buttering pans directly and dusting with flour.)

2. Sift together the flour, baking powder, baking soda, and salt.

3. Beat together the butter and sugar in a large bowl with an electric mixer until light and fluffy. Add eggs 1 at a time, beating well after each addition, then beat in vanilla. Add half of the flour mixture and mix at low speed until just blended. Add the sour cream, mixing until just combined, then add the remaining flour mixture, mixing at low speed until the batter is smooth.

4. Divide the batter between the pans, smoothing tops. Bake in the middle of the oven until the cake is springy to the touch and a tester comes out clean, 30 to 40 minutes. Cool in pans on racks 10 minutes, then invert onto racks, remove paper, and cool completely.

5. For the frosting: Melt the chocolates in a double boiler or a large metal bowl set over a saucepan of simmering water, stirring occasionally. Remove the bowl from heat, then whisk in the sour cream and vanilla. Cool to room temperature, stirring occasionally (frosting will become thick enough to spread). You must work quickly and spread the frosting before it becomes too thick. (If icing does become stiff, reheat over simmering water, then cool and try again.)

6. Trim the tops of cooled cake layers with a long serrated knife if necessary to make flat and level. Halve each layer horizontally with a serrated knife to make a total of 4 layers.

7. Put 1 cake layer on a cake plate and spread with 3/4 cup frosting. Layer remaining cake layers using 3/4 cup frosting between each layer. Frost top and sides of cake with remaining frosting.

Note:
This batter can be baked in a 13 x 9 x 2-inch pan 50 to 55 minutes; or in 30 (1/2-cup) muffin cups about 25 minutes.