Red Velvet Cake with Cream Cheese Frosting

We can thank Martha for this one. Jake requested it for his birthday. It was good, but it's not the easiest recipe in the world. I guess a man can make a tough request for his 30th birthday!

Red Velvet Cake
Martha Stewart, submitted by Emily Hutchings

(Makes one 8-inch cake)

3/4 cup unsalted butter, room temperature, plus more for pans
2 1/2 cups cake flour (not self-rising), sifted, plus more for pans
3 tablespoons unsweetened cocoa powder
1 1/2 teaspoons baking powder
2 cups sugar
3 large eggs
1 teaspoon pure vanilla extract
1/4 teaspoon salt
2 one-ounce bottles liquid red food coloring
3 tablespoons lukewarm water
1 cup buttermilk
1 teaspoon baking soda
1 tablespoon white vinegar

Preheat oven to 350 degrees. Butter two 8-by-2-inch round cake pans. Line with parchment paper, and butter again. Dust with flour, and tap out the excess; set aside. In a medium bowl, sift together cake flour, cocoa, and baking powder; set aside. In the bowl of an electric mixer fitted with the paddle attachment, combine the butter and sugar, and beat on medium speed until light and fluffy, about 15 minutes. Add eggs, one at a time, beating well after each addition. Add vanilla, salt, food coloring, and water; beat, scraping down the sides of the bowl, until well combined. Add reserved dry ingredients in additions, alternating with the buttermilk; beat on low speed until well combined. In a small bowl, stir together baking soda and vinegar; add to batter. Beat on medium speed for 10 seconds. Be sure not to over beat. Divide batter between prepared pans, and bake until a cake tester inserted into the center comes out clean, 25 to 30 minutes. Remove pans from oven, and transfer to a wire rack to cool, about 15 minutes. Turn cakes out onto rack; let stand until completely cool. Using a serrated knife, trim tops of cakes so surfaces are level. Place a layer on a cake stand or cardboard round, and spread about 1/3 of the frosting over top. Place the second layer on top, and spread with the remaining frosting over the tops and sides of assembled cake. Transfer to refrigerator, and chill until ready to serve.

Cream Cheese Frosting

(Makes 2 cups)

1/2 cup (1 stick) unsalted butter, room temperature
1 (8-ounce) cream cheese, room temperature
1 cup confectioners' sugar, sifted
1 teaspoon pure vanilla extract
1/4 cup finely chopped walnuts
Place butter in bowl of an electric mixer fitted with the paddle attachment, and beat on medium-high speed until light and fluffy, about 2 minutes. Add cream cheese, and beat until well combined and fluffy, about 2 minutes more. Add sugar and vanilla, and beat until combined, about 2 minutes. Fold in walnuts.