Sour Cream Butter Cake
Per 1 slice
4 egg yolks
2⁄3 cup sour cream
11⁄2 teaspoons vanilla
2 cups sifted cake flour
1 cup sugar
1⁄2 teaspoon baking powder
1⁄2 teaspoon baking soda
1⁄2 teaspoon salt
6 ounces (11⁄2 sticks) unsalted butter, softened to room temperature
Preheat oven to 350°F. Grease a 9-inch cake pan, dust it with flour, and line the bottom with waxed paper. In a bowl, whisk together the yolks, 1⁄4 of the sour cream, and the vanilla. In a large, separate bowl, mix the flour, sugar, baking powder, baking soda, and salt; whisk vigorously to combine.
Add the butter and remaining sour cream to the flour mixture, and mix well until flour is completely moistened. Add the egg mixture to the flour mixture in 3 separate additions, mixing between each addition. Pour into prepared cake pan.
Bake in the middle of the oven until a toothpick inserted in the center comes out clean, usually about 35–40 minutes. Start checking at 25 minutes, since oven temperatures and ingredient characteristics vary, and it might be done quicker. Cool 10 minutes, then take out of pan and cool completely on a wire rack.
If frosting cake, prepare by cutting cooled cakes laterally in half and frost both sections, then stack smooth sides, and refrigerate to set.