Ingredients
Method
Preparation
- Heat the oven to 325°F. Coat three 6-inch cake pans with nonstick spray, and line each bottom with a parchment circle.
- In the bowl of a stand mixer, stir the cake flour, all-purpose flour, sugar, baking powder, baking soda, and salt together on low speed.
- Add the softened butter and mix on medium-low for about 1 minute, until the mixture looks like damp sand.
- Add the whole eggs and the extra yolk, then mix until fully blended. Scrape down the bowl, and add the sour cream, milk, and vanilla. Beat on medium speed for 2 to 3 minutes.
- Divide the batter evenly among the three prepared pans.
Baking
- Bake for 35 to 45 minutes, until edges are golden and a toothpick comes out clean from the thickest part.
- Cool the layers completely in the pans for about 1 hour, then turn them out carefully.
Frosting and Assembly
- For the frosting, combine the butter, salt, cocoa, and about one-third of the powdered sugar in a large bowl. Beat on medium speed until combined.
- Add the remaining powdered sugar in two batches, beating after each addition. Then add the cream and vanilla and whip on medium-high until light and fluffy.
- Stack and frost the cooled layers, and store the cake covered until serving.
Notes
Store the frosted cake covered at room temperature for up to 1 day. Refrigerate for up to 5 days and freeze individual slices or unfrosted layers for up to 2 months.
