My mom is a self-proclaimed chocoholic, therefore deciding on a birthday cake for her was an easy decision. I knew I wanted something with intense chocolate flavor, and a soft whipped buttercream. The addition of the sour cream makes this cake incredibly moist and tender. In fact, it is so soft that I suggest freezing the cakes briefly before assembling the cake to avoid the cakes breaking.
After learning the beauty of swiss meringue buttercream, I knew I wanted to try a chocolate version of it. I was not disappointed. The frosting has been known to be fussy to make, but the results are incredible. The frosting is light and fluffy and balances the cake nicely. This makes a huge cake, so be prepared to feed lots of people, or have plenty of leftovers.
Chocolate Sour Cream Cake
Yields: An 8-inch triple-layer cake
2 cups all-purpose flour
2 1/2 cups sugar
3/4 cup unsweetened cocoa powder, preferably Dutch process
2 teaspoons baking soda
1 teaspoon salt
1 cup canola or vegetable oil
1 cup sour cream
1 1/2 cups water
2 tablespoons distilled white vinegar
1 teaspoon vanilla extract
Preheat the oven to 350 degrees F. Grease the bottoms and sides of three 8-inch round cake pans. Line the bottom of each pan with a round of parchment or waxed paper and butter the paper.
Sift the flour, sugar, cocoa powder, baking soda, and salt into a large bowl. Whisk to combine them well. Add the oil and sour cream and whisk to blend. Gradually beat in the water. Blend in the vinegar and vanilla. Whisk in the eggs and beat until well blended. Scrape down the sides of the bowl and be sure the batter is well mixed. Divide among the 3 prepared cake pans.
Bake for 30 to 35 minutes, or until a cake tester or wooden toothpick inserted in the center comes out almost clean. Let cool in the pans for about 20 minutes. Invert onto wire racks, carefully peel off the paper liners, and let cool completely. (These cakes are very soft, so I would suggest freezing them slightly before assembling the cake. It will make your life easier!)
Chocolate Swiss Meringue Buttercream
Yields: About 4 cups
4 sticks unsalted butter, cut into tablespoons
2 cups sugar
10 egg whites
8 ounces bittersweet chocolate, melted.
In a double boiler, whisk together the egg whites and sugar on low heat until the sugar has dissolved (about 5 minutes).
Using the whisk attachment on your stand mixer, whip the egg whites until they start to form stiff peaks.
Adding 1 cube at a time, slowly add the butter and continue to mix. The meringue will deflate, but don’t worry, its ok!
If the mixture is soupy after adding the butter, try chilling the frosting for 15 minutes until firm, and then whip again. If this doesn’t work, add a cube or two more of butter and continue to whip. It will thicken up!
Shortly thereafter the mixture should smooth out and you will have your swiss meringue buttercream. Whip in the vanilla and slowly add the chocolate. If still hot, do not add the melted chocolate all at once – you could melt the buttercream.